Support for Web Serial in Firefox 151 for Desktop Firefox can now connect directly to microcontrollers, development boards, 3D printers, power meters, and other serial-connected hardware from the web. Starting in Firefox 151 for Desktop, support for the Web Serial API allows web applications to communicate with compatible devices without requiring native software. Web Serial […] The post Announcing Web…
#firefox
136 posts
21 May
7 May
Two weeks ago we announced that we had identified and fixed an unprecedented number of latent security bugs in Firefox with the help of Claude Mythos Preview and other AI models. In this post, we’ll go into more detail about how we approached this work, what we found, and advice for other projects on making […] The post Behind the…
5 May
The open web is a critical platform for applications that handle highly sensitive data, from private communications to financial transactions and medical records. Traditionally, servers are trusted to deliver the appropriate code and resources for their web applications to browsers, who then provide a secure and isolated environment for their execution. In some circumstances, this […] The post Trustworthy JavaScript…
25 Mar
In January, we introduced our Nightly package for RPM-based Linux distributions. Today, we are thrilled to announce it is now available for Firefox Beta! Firefox Beta is great for testing your sites in a version of Firefox that will reach regular users in the coming weeks. If you find any issues, please file them on […] The post Firefox Developer…
24 Feb
Cross-site scripting (XSS) remains one of the most prevalent vulnerabilities on the web. The new standardized Sanitizer API provides a straightforward way for web developers to sanitize untrusted HTML before inserting it into the DOM. Firefox 148 is the first browser to ship this standardized security enhancing API, advancing a safer web for everyone. We […] The post Goodbye innerHTML,…
12 Feb
The Interop Project is a cross-browser initiative to improve web compatibility in areas that offer the most benefit to both users and developers. The group, including Apple, Google, Igalia, Microsoft, and Mozilla, takes proposals of features that are well defined in a sufficiently stable web standard, and have good test suite coverage. Then, we come […] The post Launching Interop…
19 Aug 2025
Firefox is now the first and the only browser to deploy fast and comprehensive certificate revocation checking that does not reveal your browsing activity to anyone (not even to Mozilla). Tens of millions of TLS server certificates are issued each day to secure communications between browsers and websites. These certificates are the cornerstones of ubiquitous […] The post CRLite: Fast,…
25 Mar 2025
Beginning in version 138, Firefox will offer an alternative to DLL injection for Data Loss Prevention (DLP) deployments in enterprise environments. DLL Injection DLL injection into Firefox is a topic we’ve covered on the Hacks blog before. In 2023, we blogged about the Firefox capability to let users block third-party DLLs from being loaded. We […] The post Improving Firefox…
13 Feb 2025
Interop 2025 continues the mission to make the web more consistent across browsers, building on 2024’s 95% interoperability score. This year, 19 focus areas target key developer needs and long-standing issues, including WebRTC improvements, Storage Access API, and CSS Zoom. The post Launching Interop 2025 appeared first on Mozilla Hacks - the Web developer blog.
4 Dec 2024
Mozilla and Filament have introduced Uniffi for React Native, a tool that allows developers to leverage the safety and performance benefits of Rust in cross-platform React Native apps. The post Introducing Uniffi for React Native: Rust-Powered Turbo Modules appeared first on Mozilla Hacks - the Web developer blog.
7 Aug 2024
We’re pleased to announce that, as of version 23, the Puppeteer browser automation library now has first-class support for Firefox. This means that it’s now easy to write automation and perform end-to-end testing using Puppeteer, and run against both Chrome and Firefox. The post Announcing Official Puppeteer Support for Firefox appeared first on Mozilla Hacks - the Web developer blog.
27 Jun 2024
Process separation remains one of the most important parts of the Firefox security model and securing our IPC (Inter-Process Communication) interfaces is crucial to keep privileges in the different processes separated. We take a more detailed look at our newest tool for finding vulnerabilities in these interfaces – snapshot fuzzing. The post Snapshots for IPC Fuzzing appeared first on Mozilla…
31 May 2024
Firefox 130 will introduce an experimental new capability to automatically generate alt-text for images using a fully private on-device AI model. The feature will be available as part of Firefox’s built-in PDF editor, and our end goal is to make it available in general browsing for users with screen readers. The post Experimenting with local alt text generation in Firefox…
25 Apr 2024
When Mozilla’s Innovation group first launched the llamafile project late last year, we were thrilled by the immediate positive response from open source AI developers. It’s become one of Mozilla’s top three most-favorited repositories on GitHub, attracting a number of contributors, some excellent PRs, and a growing community on our Discord server. The post Llamafile’s progress, four months in appeared…
23 Apr 2024
In this blog post, we delve into the motivations for choosing Rust for our crash reporter, outline the unique challenges of designing an application that operates when the main browser has failed, and discuss the new architecture we've implemented. We also share insights into the technical nuances of the implementation, demonstrating how Rust's features are leveraged to handle crashes more…
11 Mar 2024
In collaboration with the other major browser engine developers, Mozilla is thrilled to announce Speedometer 3 today. Like previous versions of Speedometer, this benchmark measures what we think matters most for performance online: responsiveness. But today’s release is more open and more challenging than before, and is the best tool for driving browser performance improvements that we’ve ever seen. The…
1 Feb 2024
Following the success of Interop 2023, we are pleased to confirm that the project will continue in 2024 with a new selection of focus areas, representing areas of the web platform where we think we can have the biggest positive impact on users and web developers. The post Announcing Interop 2024 appeared first on Mozilla Hacks - the Web developer…
29 Jan 2024
During the Firefox 120 beta cycle, a new crash signature appeared on our radars with significant volume. Engineers working on Firefox, explore the subtle pitfalls of combining compiler flags. The post Option Soup: the subtle pitfalls of combining compiler flags appeared first on Mozilla Hacks - the Web developer blog.
12 Dec 2023
Puppeteer now supports the next-generation, cross-browser WebDriver BiDi standard. This new protocol makes it easy for web developers to write automated tests that work across multiple browser engines. The post Puppeteer Support for the Cross-Browser WebDriver BiDi Standard appeared first on Mozilla Hacks - the Web developer blog.
30 Nov 2023
A month ago, we introduced our Nightly package for Debian-based Linux distributions. Today, we are proud to announce we made our .deb package available for Developer Edition and Beta! The post Firefox Developer Edition and Beta: Try out Mozilla’s .deb package! appeared first on Mozilla Hacks - the Web developer blog.
16 Nov 2023
Mozilla has just launched the AI Guide, a collaborative hub for developers to join forces, inspire each other, and lead the way in groundbreaking generative AI advancements. The AI Guide’s initial focus begins with language models and the aim is to become a collaborative community-driven resource covering other types of models. The post Mozilla AI Guide Launch with Summarization Code…
31 Oct 2023
To deliver against our vision and enable a better online experience for everyone, we’ve been working hard on making Firefox even faster. We’re extremely happy to report that this has resulted in a significant improvement in speed over the past year. The post Down and to the Right: Firefox Got Faster for Real Users in 2023 appeared first on Mozilla…
12 Oct 2023
Protecting user privacy is a core element of Mozilla’s vision for the web and the internet at large. In pursuit of this vision, we’re pleased to announce new partnerships with Fastly and Divvi Up to deploy privacy-preserving technology in Firefox. The post Built for Privacy: Partnering to Deploy Oblivious HTTP and Prio in Firefox appeared first on Mozilla Hacks -…
5 Sept 2023
Firefox performance on Vue.js has improved significantly throughout the year. Most recently, we sped up reactivity with Proxy optimizations. This change landed in Firefox 118, so it’s currently on Beta and will ride along to Release by the end of September. The post Faster Vue.js Execution in Firefox appeared first on Mozilla Hacks - the Web developer blog.
8 Aug 2023
This blog post will walk through how we developed UniFFI: a Rust library for auto-generating foreign language bindings. We will walk through some of the issues that arose along the way and how we handled them. The post Autogenerating Rust-JS bindings with UniFFI appeared first on Mozilla Hacks - the Web developer blog.
30 Mar 2023
In Firefox 110, users now have the ability to control which third-party DLLs are allowed to load into Firefox processes. Let’s talk about what this means and when it might be useful. The post Letting users block injected third-party DLLs in Firefox appeared first on Mozilla Hacks - the Web developer blog.
1 Feb 2023
Interop 2022 showed significant improvements in the interoperability of multiple platform features, along with several cross-browser investigations that looked into complex, under-specified, areas of the platform where interoperability has been difficult to achieve. Building on this, we're pleased to announce Interop 2023, the next iteration of the Interop project. The post Announcing Interop 2023 appeared first on Mozilla Hacks -…
31 Jan 2023
Last March we announced the Interop 2022 project, a collaboration between Apple, Bocoup, Google, Igalia, Microsoft, and Mozilla to improve the quality and consistency of their implementations of the web platform. Now that it's 2023 and we're deep into preparations for the next iteration of Interop, it's a good time to reflect on how the first year of Interop has…
7 Dec 2022
A product is first an idea, then a project, and then a prototype. Here, at Mozilla, our awesome community is there every step of the way to support and contribute to our products. None of what we do would be possible without this multicultural, multilingual community of like-minded people working together to be a better internet. The post How the…
22 Nov 2022
We break down how we reduced Firefox out-of-memory crashes on Windows with a simple trick. Poorly behaving web pages and apps are no longer capable of crashing the browser by exhausting memory. The post Improving Firefox stability with this one weird trick appeared first on Mozilla Hacks - the Web developer blog.
31 Oct 2022
The MDN Web Docs team recently undertook a project to revamp and reorganize the “Contribution Docs”. These are all the pages on MDN that describe what's what – the templates and page structures, how to perform a task on MDN, how to contribute to MDN, and the community guidelines to follow while contributing to this massive open source project. The…
10 Oct 2022
If you're running Firefox on macOS you might have noticed that its responsiveness has improved significantly in version 103, especially if you've got a lot of tabs, or when your machine is busy running other applications at the same time. This improvement was achieved via a small change in how locking is implemented within Firefox's memory allocator. The post Improving…
29 Jun 2022
Firefox Translations is a website translation add-on that provides an automated translation of web content. In this article, we will discuss the technical challenges around the development of the translation engine and how we solved them to build a usable Firefox Translations add-on. The post Neural Machine Translation Engine for Firefox Translations add-on appeared first on Mozilla Hacks - the…
23 Jun 2022
For the last year, we've been working on the development of rust-minidump, a pure-Rust replacement for the minidump-processing half of google-breakpad. The final part in this series takes you through fuzzing rust-minidump. The post Fuzzing rust-minidump for Embarrassment and Crashes – Part 2 appeared first on Mozilla Hacks - the Web developer blog.
14 Jun 2022
For the last year, we've been working on the development of rust-minidump, a pure-Rust replacement for the minidump-processing half of google-breakpad. The first in this two-part series explains what minidumps are, and how we made rust-minidump. The post Everything Is Broken: Shipping rust-minidump at Mozilla – Part 1 appeared first on Mozilla Hacks - the Web developer blog.
7 Jun 2022
The Bergamot project is a collaboration between Mozilla, University of Edinburgh, Charles University in Prague, the University of Sheffield, and University of Tartu with funding from the European Union’s Horizon 2020 research and innovation programme. It brings MT to the local environment, providing small, high-quality, CPU optimized NMT models. The Firefox Translations web extension utilizes proceedings of project Bergamot and…
12 May 2022
Firefox uses a multi-process model for additional security and stability while browsing: Web Content (such as HTML/CSS and Javascript) is rendered in separate processes that are isolated from the rest of the operating system and managed by a privileged parent process. This way, the amount of control gained by an attacker that exploits a bug in a content process is…
21 Apr 2022
On March 1st, 2022, MDN Web Docs released a new design and a new brand identity. Overall, the community responded to the redesign enthusiastically and we received many positive messages and kudos. We also received valuable feedback on some of the things we didn’t get quite right, like the browser compatibility table changes as well as some accessibility and readability…
13 Apr 2022
We’re pleased to announce that we have partnered with Center for Humane Tech, a nonprofit organization that radically reimagines the digital infrastructure. Its mission is to drive a comprehensive shift toward humane technology that supports the collective well-being, democracy and shared information environment. The post Mozilla partners with the Center for Humane Technology appeared first on Mozilla Hacks - the…
30 Mar 2022
In Firefox 98, we’re shipping a new version of the existing Performance panel. This panel is now based on the Firefox profiler tool that can be used to capture a performance profile for a web page, inspect visualized performance data and analyze it to identify slow areas. The post Performance Tool in Firefox DevTools Reloaded appeared first on Mozilla Hacks…
17 Mar 2022
For both MDN and Open Web Docs (OWD), transparency is paramount to our missions. With the upcoming launch of MDN Plus, we believe it’s a good time to talk about how our two organizations work together, and if there is a financial relationship between us. Here is an overview of how our missions overlap and how they differ, and how…
3 Mar 2022
Writing high quality standards is a necessary first step to an interoperable web platform, but ensuring that browsers are consistent in their behavior requires an ongoing process. Browsers must work to ensure that they have a shared understanding of web standards, and that their implementation matches that understanding. Interop 2022 is a cross-browser initiative to find and address the most…
1 Mar 2022
If you’ve accessed the MDN website today, you probably noticed that it looks quite different. We hope it’s a good different. Let us explain! In mid-2021 we started to think about modernizing MDN’s design, to create a clean and inviting website that makes navigating our 44,000 articles as easy as possible. We wanted to create a more holistic experience for…
15 Feb 2022
Chrome and Firefox will reach version 100 in a couple of months. This has the potential to cause breakage on sites that rely on identifying the browser version to perform business logic. This post covers the timeline of events, the strategies that Chrome and Firefox are taking to mitigate the impact, and how you can help. The post Version 100…
8 Feb 2022
Before we roll out State Partitioning for all Firefox users, we intend to make a few privacy and ergonomic improvements to the Storage Access API. In this blog post, we’ll detail a few of the new changes we made. The post Improving the Storage Access API in Firefox appeared first on Mozilla Hacks - the Web developer blog.
2 Feb 2022
On January 13th 2022, Firefox became unusable for close to two hours for users worldwide. This incident interrupted many people’s workflow. This post highlights the complex series of events and circumstances that, together, triggered a bug deep in the networking code of Firefox. What Happened? Firefox has a number of servers and related infrastructure that […] The post Retrospective and…
18 Jan 2022
If you’ve ever built anything with web technologies, you’re probably familiar with MDN Web Docs. With about 13,000 pages documenting how to use programming languages such as HTML, CSS and JavaScript, the site has about 8,000 people using it at any given moment. MDN relies on contributors to help maintain its ever-expanding and up to date documentation. We reached out…
30 Dec 2021
Sara Soueidan is an independent Web UI and design engineer, author, speaker, and trainer from Lebanon. Currently, she’s working on a new course, "Practical Accessibility," meant to teach devs and designers ways to make their products accessible. We chatted with Sara about front-end web development, the importance of design and her appreciation of birds. The post Hacks Decoded: Sara Soueidan,…
6 Dec 2021
In Firefox 95, we're shipping a novel sandboxing technology called RLBox — developed in collaboration with researchers at the University of California San Diego and the University of Texas — that makes it easy and efficient to isolate subcomponents to make the browser more secure. This technology opens up new opportunities beyond what's been possible with traditional process-based sandboxing, and…
30 Nov 2021
Seyi Akiwowo’s reputation precedes her. Akiwowo is the founder of Glitch, an organization that seeks to end online abuse. We spoke with Seyi over video chat to learn about what drives her, why she does what she does and what she’d be doing if not battling trolls online for a living. The post Hacks Decoded: Seyi Akiwowo, Founder of Glitch…
20 Oct 2021
Welcome to our Hacks: Decoded Interview series! We spoke with Thomas Park over email about coding, his favourite apps and his past life at Mozilla. Thomas is the founder of Codepip, a platform he created for coding games that helps people learn HTML, CSS, JavaScript, etc. The most popular game is Flexbox Froggy. The post Hacks Decoded: Thomas Park, Founder…
8 Oct 2021
Firefox 93 comes with lots of lovely updates including AVIF image format support, filling of XFA-based forms in its PDF viewer and protection against insecure downloads by blocking downloads relying on insecure connections. The post Lots to see in Firefox 93! appeared first on Mozilla Hacks - the Web developer blog.
7 Oct 2021
Last year, during lockdown, many discovered the importance of PDF forms when having to deal remotely with administrations and large organizations like banks. Firefox supported displaying PDF forms, but it didn’t support filling them: users had to print them, fill them by hand, and scan them back to digital form. We decided it was time to reinvest in the PDF…
6 Oct 2021
In a world where data and AI are reshaping society, people currently have no tangible way to put their data to work for the causes they believe in. To address this, we built the Rally platform, a first-of-its-kind tool that enables you to contribute your data to specific studies and exercise consent at a granular level. Mozilla Rally puts you…
5 Oct 2021
Starting with Firefox 93, Firefox will monitor available system memory and, should it ever become so critically low that a crash is imminent, Firefox will respond by unloading memory-heavy but not actively used tabs. This feature is currently enabled on Windows and will be deployed later for macOS and Linux as well. The post Tab Unloading in Firefox 93 appeared…
8 Sept 2021
Release time comes around so quickly! This month we have quite a few CSS updates, along with the new Object.hasOwn() static method for JavaScript. The post Time for a review of Firefox 92 appeared first on Mozilla Hacks - the Web developer blog.
18 Aug 2021
Last month we removed a bunch of content from MDN. MDN is 16 years old (and yes it can drink in some countries), all that time ago it was a great place for all of Mozilla to document all of their things. As MDN evolved and the web reference became our core content, other areas became less relevant to the…
3 Aug 2021
Last month, Gregor Weber and Peter Bengtsson added an autocomplete search to MDN Web Docs, that allows you to quickly jump straight to the document you're looking for by typing parts of the document title. This is the story about how that's implemented. The post How MDN’s autocomplete search works appeared first on Mozilla Hacks - the Web developer blog.
20 Jul 2021
As we’re all aware by now, we made some big platform changes at the end of 2020. Whilst the big move has happened, it’s given us a great opportunity to clear out the cupboards and closets. The post Spring Cleaning MDN: Part 1 appeared first on Mozilla Hacks - the Web developer blog.
13 Jul 2021
As the summer rolls around for those of us in the northern hemisphere, temperatures are high and unwinding with a cool ice tea is high on the agenda. Isn't it lucky then that Background Update is here for Windows, which means Firefox can update even if it's not running. We can just sit back and relax! Also this release we…
8 Jun 2021
When implementing a language feature for JavaScript, an implementer must make decisions about how the language in the specification maps to the implementation. Private fields is an example of where the specification language and implementation reality diverge, at least in SpiderMonkey– the JavaScript engine which powers Firefox. To understand more, I’ll explain what private fields are, a couple of models…
1 Jun 2021
Firefox 89 has smartened up and brings with it a slimmed-down, slightly more minimalist interface. Along with this new look, we get some great styling features including a force-colours feature for media queries and better control over how fonts are displayed. The long-awaited top-level await keyword for JavaScript modules is now enabled, as well as the PerformanceEventTiming interface, which is…
19 May 2021
Roughly a year ago at Mozilla we started an effort to improve Firefox stability on Linux. This effort quickly became an example of good synergies between FOSS projects. The post Improving Firefox stability on Linux appeared first on Mozilla Hacks - the Web developer blog.
18 May 2021
Like any web browser, Firefox loads code from untrusted and potentially hostile websites and runs it on your computer. To protect you against new types of attacks from malicious sites and to meet the security principles of Mozilla, we set out to redesign Firefox on desktop. The post Introducing Firefox’s new Site Isolation Security Architecture appeared first on Mozilla Hacks…
19 Apr 2021
April is upon us, and we have a most timely release for you — Firefox 88. In this release you will find a bunch of nice CSS additions including :user-valid and :user-invalid support and image-set() support, support for regular expression match indices, removal of FTP protocol support for enhanced security, and more! This blog post […] The post Never too…
16 Apr 2021
Support for QUIC and HTTP/3 is now enabled by default in Firefox Nightly and Firefox Beta and we are planning to start a rollout on the release in Firefox Stable Release 88. HTTP/3 will be available by default by the end of May. The post QUIC and HTTP/3 Support now in Firefox Nightly and Beta appeared first on Mozilla Hacks…
6 Apr 2021
We successfully deployed ThreadSanitizer in the Firefox project to eliminate data races in our remaining C/C++ components. In the process, we found several impactful bugs and can safely say that data races are often underestimated in terms of their impact on program correctness. We recommend that all multithreaded C/C++ projects adopt the ThreadSanitizer tool to enhance code quality. The post…
23 Mar 2021
Nearing the end of March now, and we have a new version of Firefox ready to deliver some interesting new features to your door. This month, we've got some rather nice DevTools additions in the form of prefers-color-scheme media query emulation and toggling :target pseudo-classes, some very useful additions to editable DOM elements: the beforeinput event and getTargetRanges() method, and…
26 Feb 2021
The internet was set on fire (pun intended) this week, by what I'm calling 'fox gate', and chances are you might have seen a meme or two about the Firefox logo. Many people were pulling up for a battle royale because they thought we had scrubbed fox imagery from our browser. We can confirm, that this is definitely not happening.…
23 Feb 2021
Looking into the near distance, we can see the end of February loitering on the horizon, threatening to give way to March at any moment. To keep you engaged until then, we’d like to introduce you to Firefox 86. The post A Fabulous February Firefox — 86! appeared first on Mozilla Hacks - the Web developer blog.
State Partitioning is the technical term for a new privacy feature in Firefox called Total Cookie Protection, which will be available in ETP Strict Mode in Firefox 86. This article shows how State Partitioning works inside of Firefox and explains what developers of third-party integrations can do to stay compatible with the latest changes. The post Introducing State Partitioning appeared…
9 Feb 2021
Mozilla has been fuzzing Firefox and its underlying components for a while. It has proven itself to be one of the most efficient ways to identify quality and security issues. In general, we apply fuzzing on different levels: there is fuzzing the browser as a whole but a significant amount of time is also spent on fuzzing isolated code (e.g.…
26 Jan 2021
To wrap up January, we are proud to bring you the release of Firefox 85. In this version we are bringing you support for the :focus-visible pseudo-class in CSS and associated devtools, , and the complete removal of Flash support from Firefox. We’d also like to invite you to preview two exciting new JavaScript features in the current Firefox Nightly…
21 Jan 2021
As a member of Mozilla’s fuzzing team, our job is not only to find bugs, but to do what we can to help get those bugs fixed as quickly as possible. To further reduce the delay in getting these bugs fixed, we wanted to automate as much of this process as possible. This effort resulted in the development of Bugmon;…
20 Jan 2021
The release of Apple Silicon-based Macs at the end of last year generated a flurry of news coverage and some surprises at the machine’s performance. This post details some background information on the experience of porting Firefox to run natively on these CPUs. The post Porting Firefox to Apple Silicon appeared first on Mozilla Hacks - the Web developer blog.
12 Jan 2021
It’s clear that WebDriver needs to grow to meet the capabilities of DevTools-based automation. However, that process will take time, and we want more developers to be able to run their automated tests in Firefox today. To that end, we have shipped an experimental implementation of parts of CDP in Firefox Nightly, specifically targeting the use cases of end-to-end testing…
17 Dec 2020
Testing web applications can be a challenge. At Mozilla, we see that as a call to action. With our commitment to building a better Internet, we want to provide web developers with the tools they need to build great web experiences – including great tools for testing. In this series of posts, we will explore the current web-application testing landscape…
15 Dec 2020
As December ushers in the final curtain for this rather eventful year, there is time left for one more Firefox version to be given its wings. Firefox 84 includes some interesting new features including tab order inspection, complex selector support in :not(), the PerformancePaintTiming API, and more! The post And now for … Firefox 84 appeared first on Mozilla Hacks…
17 Nov 2020
This week the Servo project took a significant next step in bringing community-led transformative innovations to the web by announcing it will be hosted by the Linux Foundation. Mozilla is pleased to see Servo, which began as a research effort in 2012, open new doors that can lead it to ever broader benefits for users and the web. Working together,…
Did November spawn a monster this year? In truth, November has given us a few snippets of good news, far from the least of which is the launch of Firefox 83! In this release we’ve got a few nice additions, including Conical CSS gradients, overflow debugging in the Developer Tools, enabling of WebRender across more platforms, and more besides. The…
13 Nov 2020
With Warp (also called WarpBuilder) we’re making big changes to our JIT (just-in-time) compilers, resulting in improved responsiveness, faster page loads and better memory usage. The new architecture is also more maintainable and unlocks additional SpiderMonkey improvements. This post explains how Warp works and how it made SpiderMonkey faster. The post Warp: Improved JS performance in Firefox 83 appeared first…
20 Oct 2020
As October ushers in the tail-end of the year, we are pushing Firefox 82 out the door. This time around we finally enable support for the Media Session API, provide some new CSS pseudo-selector behaviours, close some security loopholes involving the Window.name property, and provide inspection for server-sent events in our developer tools. The post Coming through with Firefox 82…
9 Oct 2020
This post will describe my recent work on Cranelift as part of my day job at Mozilla. In this post, I will set some context and describe the instruction selection problem. In particular, I’ll talk about a revamp to the instruction selector and backend framework in general that we’ve been working on. The post A New Backend for Cranelift, Part…
1 Oct 2020
Porting an established static website from one generator to another can be daunting. In this post, Add-ons Engineering Manager Stuart Colville recounts the experience of migrating Firefox Extension Workshop, Mozilla’s site for Firefox-specific extension development resources, from the Ruby-based site generator Jekyll to JavaScript-based Eleventy. The post To Eleventy and Beyond appeared first on Mozilla Hacks - the Web developer…
4 Aug 2020
Browsers are changing the default value of the SameSite attribute for cookies from None to Lax. This will greatly improve security for users. However, some web sites may depend (even unknowingly) on the old default, potentially resulting in site breakage. At Mozilla, we are slowly introducing this change. And we urge web developers to test their sites with the new…
28 Jul 2020
Firefox 79 offers a new Promise method, more secure target=_blank links, logical assignment operators, tooling improvements for better JavaScript debugging, and many other updates of interest to web developers. In addition, shared memory is back at last, with a safer implementation. The post Firefox 79: The safe return of shared memory, new tooling, and platform updates appeared first on Mozilla…
21 Jul 2020
At Mozilla, we want the web to be capable of running high-performance applications so that users and content authors can choose the safety, agency, and openness of the web platform. Shared-memory multi-threading is an essential low-level building block for high-performance applications. However, keeping users safe is paramount, which is why shared memory and high-resolution timers were effectively disabled at the…
7 Jul 2020
When we talk about the contrast of a page, or contrast between web elements, we’re assessing how color choices impact readability. For visitors with low vision, web pages with low or insufficient contrast can be hard to use. In this article, we’ll walk through the design and implementation of the prefers-contrast media query in Firefox, and look at why it's…
30 Jun 2020
New in Firefox 78: DevTools improvements, new regex engine, and abundant web platform updates
Mozilla HacksFirefox 78 heads heads out the door with a new regex engine, updates to the ECMAScript Intl API, new CSS selectors, enhanced support for WebAssembly, some important WebExtensions API updates, and many improvements to the Firefox Developer Tools. The post New in Firefox 78: DevTools improvements, new regex engine, and abundant web platform updates appeared first on Mozilla Hacks -…
18 Jun 2020
Yulia Startsev, a JavaScript engineer on Firefox's SpiderMonkey team, introduces her new Twitch stream called Compiler Compiler. In the three opening interactive episodes, we get an inside look at how the JavaScript Specification, ECMA-262, is implemented in SpiderMonkey, by reading the spec and fixing issues in the implementation. The post Compiler Compiler: A Twitch series about working on a JavaScript…
9 Jun 2020
Tenemos ante nosotros una nueva versión estable de Firefox. La versión 77 viene con varias novedades para los desarrolladores web. En este artículo se presenta simplemente un conjunto de los aspectos más destacados. Para conocer todos los detalles, consulte lo siguiente: Firefox 77 para desarrolladores en MDN Notas de la versión de usuario final de […] The post Nuevo en…
2 Jun 2020
Firefox 77 is now available with a variety of developer tool updates and new web platform features. With your feedback, we've removed performance bottlenecks, resulting in faster, leaner JavaScript debugging. We also report on some changes to Firefox extensions, including fewer permission requests. The post New in Firefox 77: DevTool improvements and web platform updates appeared first on Mozilla Hacks…
20 May 2020
Firefox Profiler is a powerful web-based performance analysis interface featuring call trees, stack charts, flame graphs, and more. All data filtering, zooming, slicing, and transformation actions are preserved in shareable URLs. FunctionTrace is a low-overhead profiler that runs on unmodified Python applications. Integrated with Firefox, it's a new breed of analysis tool project built conveniently on top of the Firefox…
13 May 2020
Hola amigos, espero que todos estén bien y se mantengan sanos y salvos. Cada nueva versión de nuestro navegador favorito viene siempre con una buena pizca de expectación, ¡y ya estamos aquí con Firefox 76! El soporte de la plataforma web recibe algunas excelentes novedades en esta actualización, como los worklets de audio y ciertas […] The post Firefox 76:…
7 May 2020
Earlier this week, Audio Worklets landed in the release of Firefox 76. We’re ready to start bridging the gap between web audio and native. Developers can now leverage AudioWorklet to write arbitrary audio processing code. This exciting new functionality raises the bar for emerging web experiences like 3D games, VR, and music production. The post High Performance Web Audio with…
5 May 2020
Firefox 76 delivers great new features for web platform support, such as Audio Worklets and Intl improvements, on the JavaScript side. Also, we’ve added a number of topnotch improvements to Firefox DevTools to make JavaScript debugging and development easier and quicker. The post Firefox 76: Audio worklets and other tricks appeared first on Mozilla Hacks - the Web developer blog.
30 Apr 2020
Fuzzing, or fuzz testing, is an automated approach for testing the safety and stability of software. For the past 3 years, the Firefox fuzzing team has been developing a new fuzzer to identify security vulnerabilities in the implementation of WebAPIs in Firefox. This fuzzer leverages the WebAPIs’ own WebIDL definitions as a fuzzing grammar. The post Fuzzing Firefox with WebIDL…
21 Apr 2020
Here's an insider's look at Firefox's code quality toolchain that's been designed to manage the ongoing development and monthly releases of our desktop browser. This post explores the architecture, challenges, and ongoing evolution of the process for managing code quality and patches for dealing with 21 million lines of code. The post Engineering code quality in the Firefox browser: A…
15 Apr 2020
Incluso en los actuales tiempos de aislamiento, nuestros equipos de ingeniería han sabido adaptarse, enfocarse y trabajar duro para ofrecer otra nueva y emocionante versión de Firefox al mundo. En lo que respecta a las herramientas para desarrollador, a partir de ahora encontramos un sistema de evaluación instantánea en la consola, puntos de interrupción de […] The post Firefox 75:…
即使在隔离时期，我们的工程团队也努力适应、保持专注并努力工作，为您带来又一个令人兴奋的新版Firefox。在开发人员工具方面，您会找到控制台中的即时评估、WebSockets的事件断点，以及其他许多功能。在网络平台方面，新增的功能包括图像的HTML延迟加载、CSS min()、max()和clamp()函数、公共静态类字段以及对Web动画API支持的补充。 请照例阅读重点内容或从以下文章中找到所有新增内容的完整列表： Firefox 75开发人员必读 Firefox 75的网站兼容性 Firefox 75最终用户发行说明 开发人员工具补充 我们首先来看看75最有趣的开发人员工具。 控制台表达式即时评估 控制台中的评估表达式是探索应用程序状态、查询DOM或试用JavaScript API的快速方法。现在，Firefox的多行控制台模式已经变得更友好、更像IDE，可用于更轻松地为更长的代码制作原型。 新的即时评估会在您键入时显示当前表达式的结果预览，类似于Quokka.js 这样的编辑器。只要在Web控制台中键入的表达式没有副作用，就会在您键入时显示结果预览。 为了使预览尽可能无缝，进行了
7 Apr 2020
Firefox 75 is chock full of handy new dev tooling: instant evaluation in the web console, event breakpoints for WebSockets, and more. New web platform features include HTML lazy loading for images, the CSS min(), max(), and clamp() functions, public static class fields, and additions to Web Animations API support. The post Firefox 75: Ambitions for April appeared first on…
3 Apr 2020
Distinguished engineer Martin Thomson explains how this problem occurred, the implications for people who might be affected, and how problems of this nature might be avoided in future. To get there, we need to dig a little into how web caching works. The post Twitter Direct Message Caching and Firefox appeared first on Mozilla Hacks - the Web developer blog.
10 Mar 2020
The release of Firefox 74 is focused on security enhancements: Feature Policy, the Cross-Origin-Resource-Policy header, and removal of TLS 1.0/1.1 support. We’ve also got some new CSS text property features, the JS optional chaining operator, and additional 2D canvas text metric features, along with the usual wealth of DevTools enhancements and bug fixes. The post Security means more with Firefox…
4 Mar 2020
Optimizing the integration of Firefox Developer Tools with the SpiderMonkey JavaScript engine has resulted in many benefits, including the new asynchronous call stack tracking now available in Firefox Developer Edition. In this post you can learn how that was done, down to detailed changes to memory management. The post Future-proofing Firefox’s JavaScript Debugger Implementation appeared first on Mozilla Hacks -…
25 Feb 2020
Protecting the security and privacy of individuals is a central tenet of Mozilla’s mission. While we continue to make extensive use of both sandboxing and Rust in Firefox to address security challenges in the browser, each has its limitations. Today we’re adding a third approach to our arsenal. RLBox, a new sandboxing technology developed by researchers at the University of…
11 Feb 2020
Today we’ve released Firefox 73, with useful additions that include CSS and JavaScript updates, and numerous DevTools improvements. We’ve added to CSS logical properties, pushed performance forward in the Console and the Debugger, and improved the WebSocket inspector. Thanks to all for the ongoing DevTools feedback. The post Firefox 73 is upon us appeared first on Mozilla Hacks - the…
15 Jan 2020
A behind-the-scenes look at the evolution of the Picture-in-Picture player for the Firefox Desktop browser. This feature is now available for MacOS, Linux and Windows users. From the beginning, it's been shaped by your feedback and inputs, with user agency as a core principle of our design and development. The post How we built Picture-in-Picture in Firefox Desktop with more…
7 Jan 2020
Though we are moving to a more frequent four-week browser release cycle, the Firefox 72 release is feature-rich and full of goodies. It includes many requested DevTools' updates and improvements. We also introduce Shadow Parts and the CSS Motion Path, and useful new JavaScript features. Plus, Picture-in-picture for video is now enabled for Mac and Linux users too! The post…
17 Dec 2019
Mozilla Hacks covered plenty of interesting territory in 2019. Our most popular posts introduced experiments and special projects, and described the evolution of groundbreaking platform technologies like WebAssembly and WASI. Mozilla WebThings continued to engage attention and adoption. And interest in Firefox releases and Firefox DevTools was stronger than ever. Read on. The post Mozilla Hacks’ 10 most-read posts of…
10 Dec 2019
Have you ever wanted to know where properties on objects are read or set in your code, without having to manually add breakpoints or log statements? Watchpoints are a type of breakpoint that provide an answer to that question. They are new in the updated Debugger, available now in the Firefox 72 Developer Edition release. The post Debugging Variables With…
3 Dec 2019
Please welcome Firefox 71 to the stage! This time around, we have a plethora of new developer tools features including the web socket message inspector, console multi-line editor mode, log on events, and network panel full text search! And as if that wasn’t enough, there are important new web platform features available, like CSS subgrid, column-span, Promise.allSettled, and the Media…
13 Nov 2019
Earlier this year we decided to reduce the amount of unsolicited notification permission prompts people receive as they move around the web using the Firefox browser. This is an intrinsic part of Mozilla's commitment to putting people first when they are online. In preparation, we ran a series of studies and experiments to understand how to improve the user experience…
23 Oct 2019
The display CSS property is how we change the formatting context of an element and its children. One of the first things you will learn about CSS is that some elements are block by default, and others are inline. The display property enables switching between these states. With support currently available only in Firefox 70, it is too early to…
22 Oct 2019
Firefox 70 is released today, and includes great new features such as secure password generation with Lockwise and the new Firefox Privacy Protection Report, as well as cool additions for developers. These include DOM mutation breakpoints and inactive CSS rule indicators in the DevTools, several new CSS text properties, two-value display syntax, and JS numeric separators. In this article, we’ll…
21 Oct 2019
Have you ever landed on a web page and wondered what fonts are being used? Have you asked yourself where those fonts come from or why a particular font isn't loading? The font editor in Firefox provides answers and insights, and gives you the ability to make font changes directly, with a live preview. The post Quickly Alter Typography with…
15 Oct 2019
The Firefox DevTools team and our contributors were hard at work over the summer, getting Firefox 70 jam-packed with improvements. We are especially excited about our new WebSocket inspection feature. To use the inspector now, download Firefox Developer Edition, and open the DevTools’ Network panel to find the Messages tab. Then, keep reading to learn more about WebSockets and the…
1 Oct 2019
Today we’re launching a new video channel, with a selection of shorts to kick things off. Get started with an intro to Dark Mode on the web, by Deja Hodge. Then, Jen Simmons shows us how to access a handy third-panel in the Firefox Developer Tools. Miriam Suzanne has a video all about the ::marker pseudo-element and list counters. No…
17 Sept 2019
Building and releasing a browser is complicated and involves many players. To optimize the process, and make it more reliable for all users, over the years we’ve developed a phased release strategy that includes ‘pre-release’ channels: Firefox Nightly, Beta, and Developer Edition. Starting Q1 2020, we're making a change. We plan to start shipping a major Firefox release every 4…
5 Sept 2019
Firefox Debugger has evolved into a fast and reliable tool chain over the past several months and it’s now supporting many cool features. Though it's primarily used to debug JavaScript, did you know that you can also use Firefox to debug your TypeScript applications? Jan 'Honza' Odvarko walks through some real world examples. The post Debugging TypeScript in Firefox DevTools…
3 Sept 2019
For our latest excellent adventure, we’ve gone and cooked up a new Firefox release. Version 69 features a number of great new additions including JavaScript public instance fields, the Resize Observer and Microtask APIs, CSS logical overflow properties (e.g. overflow-block) and @supports for selectors. The post Firefox 69 — a tale of Resize Observer, microtasks, CSS, and DevTools appeared first…
30 Aug 2019
Modern web applications load and execute a lot more JavaScript code than they did just a few years ago. While JIT (just-in-time) compilers have been very successful in making JavaScript performant, we needed a better solution. We’ve added a new, generated JavaScript bytecode interpreter to the JavaScript engine in Firefox 70. Instead of writing a new interpreter from scratch, we…
31 Jul 2019
Firefox 68 landed earlier this month with a bunch of CSS additions and changes. In this blog post Rachel Andrew takes a look at some of the things you can expect to find, like Scroll Snapping done right, the ::marker pseudo-element, and new tooling in Firefox DevTools for working with CSS. The post New CSS Features in Firefox 68 appeared…
12 Jul 2019
We've been conducting an ongoing post-mortem on the add-ons outage that occurred earlier this year. There was a lot more digging to do than we expected. In addition to this updated high-level overview, we've also published our findings in detailed incident and technical reports that are now available. The post Add-Ons Outage Post-Mortem Result appeared first on Mozilla Hacks -…
9 Jul 2019
Firefox 68 is available today, sporting support for big integers, whole-page contrast checks checks for accessibility, and a completely new implementation of a core Firefox feature: the ever-awesome URL bar. Dan Callahan also reports on updated CSS scroll-snapping and other features, DOM API updates, next steps in the WebRender implementation, and more. The post Firefox 68: BigInts, Contrast Checks, and…
27 Jun 2019
Introducing the initial release of Firefox Preview (GitHub), an entire browser built from the ground up with GeckoView and Mozilla Android Components. Firefox Preview is our platform for building, testing, and delivering unique features. Though still an early preview, this is our first end-user product built completely with these new technologies. Plus, we share an update on where GeckoView is…
18 Jun 2019
The CSS Scroll Snap specification gives us a way in CSS to snap between different elements in a page or scrolling component. In this post, Rachel Andrew explains how scroll snapping works, why we had a situation where browsers were running different versions of the specification, and how that's changing. The post CSS Scroll Snap Updated in Firefox 68 appeared…
23 May 2019
With this week's release of Firefox 67, the new high performance royalty-free AV1 video decoder dav1d is now enabled by default on all desktop platforms (Windows, OSX and Linux) for both 32-bit and 64-bit systems. And work is in progress on rav1e, the Rust AV1 encoder. The post Firefox brings you smooth video playback with the world’s fastest AV1 decoder…
21 May 2019
Firefox 67 is now available in general release, bringing a faster and better JavaScript debugger, support for CSS prefers-color-scheme queries, and the initial debut of WebRender in stable Firefox. Dan Callahan walks through the highlights of browser, platform, and tooling features. The post Firefox 67: Dark Mode CSS, WebRender, and more appeared first on Mozilla Hacks - the Web developer…
16 May 2019
Script debugging is one of the most powerful and complex productivity features in the web developer toolbox. Done right, it empowers developers to fix bugs quickly and efficiently. The DevTools Debugger team – with help from our tireless developer community – has just landed updates that significantly improve performance and reliability. The post Faster smarter JavaScript debugging in Firefox DevTools…
15 May 2019
As you may have read last year, Safari, Firefox, Edge and Chrome browsers are removing support for TLS 1.0 and 1.1 in March of 2020. That means there’s less than a year to enable TLS 1.2 (and, ideally, 1.3) on your servers, otherwise all major browsers will display error pages, rather than the content your users came to see. The…
9 May 2019
Recently, Firefox had an incident in which most add-ons stopped working. This was due to an error on our end: we let one of the certificates used to sign add-ons expire which had the effect of disabling the vast majority of add-ons. Now that we’ve fixed the problem for most users and most people’s add-ons are restored, I wanted to…
17 Apr 2019
Fluent is a family of localization specifications, implementations and good practices developed by Mozilla. With Fluent, translators can create expressive translations that sound great in their language. Today we’re announcing version 1.0 of the Fluent file format specification. We’re inviting translation tool authors to try it out and provide feedback. The post Fluent 1.0: a localization system for natural-sounding translations…
9 Apr 2019
To help get bugs in front of the right Firefox engineers quickly, we developed BugBug, a machine learning tool that automatically assigns a product and component for each new untriaged bug. By presenting new bugs to triage owners faster, we hope to decrease the turnaround time to fix new issues. Check out BugBug for your own issue-tracking triage. The post…
9 Nov 2004
The Greek poet Archilochus wrote “The fox knows many things, but the hedgehog knows one big thing.” But what does the Firefox know? Both many things (tabbed browsing live bookmarks popup blocking mouse gestures extension architecture download manager small fast . . .) and one immense thing: that the power of the Internet and the … Continue reading "The Firefox…
10 Sept 2004
For the impending PR1 candidate builds (tomorrow’s, we hope): Alternate Style Sheet switcher makes a come-back thanks to Fantasai, with Ben reviewing and Asa approving. The statusbar icon won’t show up unless the page has alternate sheets, which is an improvement. There’s a View menu item to disables all author-level style sheets. Work Offline is … Continue reading "Firefox news…
25 Aug 2004
A lot of folks in the Mozilla community share the reaction Boris had to some deeply mistaken, tentative and now-aborted plans to remove View / Source and other “developer” features from Firefox. I wanted to point out that these plans were not made with agreement from me or, as far as I can tell, from … Continue reading "Everyone remain…