Update on Firefox Support for Windows XP and Vista

In approximately March, 2017, Windows XP and Vista users will automatically be moved to the Firefox Extended Support Release (ESR).

Firefox is one of the few browsers that continues to support Windows XP and Vista, and we expect to continue to provide security updates for users until September 2017. Users do not need to take additional action to receive those updates. In mid-2017, user numbers on Windows XP and Vista will be reassessed and a final support end date will be announced.

In the meantime, we strongly encourage our users to upgrade to a version of Windows that is supported by Microsoft. Unsupported operating systems receive no security updates, have known exploits, and are dangerous for you to use.  For planning purposes, enterprises using Firefox should consider September 2017 as the support end date for Windows XP and Vista.

For more information please visit the Firefox support page.

Update on Multi-Process Firefox

About four months ago, we launched multi-process Firefox to a small group of Firefox 48 users. Shortly after the carefully measured roll-out, we increased to approximately 50% of our user base. That included almost every Firefox user not using extensions. Those users have been enjoying the 400% increase in responsiveness and a 700% improvement when web pages are loading.

With Firefox 49 we deployed multi-process Firefox to users with a select set of well tested extensions. Our measurements and user feedback were all positive and so with Firefox 50 we deployed multi-process Firefox to users with a broader set of extensions, those whose authors have marked them as multi-process compatible.

Beyond Firefox 50, we have more work to do to enable multi-process Firefox for users with as yet unsupported extensions. In Firefox 51, if all testing goes according to plan, we’ll be enabling multi-process Firefox for users with extensions that are not explicitly marked as incompatible with multi-process Firefox.

In parallel to work enabling multi-process for more people using Firefox, we’re also working on additional longer term multi-process features that will further improve responsiveness and bring significant security benefits.

The first of those longer term multi-process features is to go from one content process to multiple content processes. The goal is to bring out the most from the multi process architecture, gain performance where it’s possible and minimize the impact of content process crashes. The first step is turning on a second content process in our Nightly channel. That gives us the opportunity to discover and squash bugs as we evaluate the right number of process to ultimately enable. That testing on Nightly is happening now.

The second long term multi-process feature is security sandboxing. Security Sandboxing makes use of child processes as a security boundary. Sandboxing work begins in Firefox 50 with the introduction of our first Windows sandbox. This is an early, laying the groundwork sandbox and is not yet hardened. Over the next few releases, the sandbox will be added to Mac and Linux and will become more restrictive and protective.

Multi-process Firefox has been a big undertaking but it’s already bringing positive results to our users in terms of responsiveness, stability, and security. Stay tuned to this channel for further updates as new multi-process capabilities are developed, tested, and deployed to Firefox users the world over.

What’s Next for Multi-process Firefox

By Asa Dotzler and Brad Lassey

Electrolysis is the project name for Mozilla’s efforts to split Firefox into multiple processes to improve responsiveness, stability, and security. The first phase of this work was to split Firefox into a UI process and a content process.

This first phase of enabling our multi-process architecture is making its way to some of our Firefox 48 users starting this week.  This is the biggest change we’ve ever made to Firefox, so we’re rolling it out slowly. For Firefox 48, we’re only enabling it for classes of users that our testing shows it works well for and to begin with, we’ll only enable it for 1% of those users so we can check on the stability and engagement data and make sure nothing new and bad is showing up. After that initial period, if all looks well, we’ll ramp up to 100% of those users, which will be about half of all Firefox 48 users.


If our Beta testing goes well, in Firefox 49 we will enable the multi-process architecture for users with a small set of add-ons that are known to work well with the multi-process architecture. In Firefox 50, again provided beta testing goes well, we plan to enable the multi-process architecture for users with add-ons that have either set a flag to say they are compatible or that were built with our new WebExtensions add-on API which is compatible by design. Eventually we will enable the multi-process architecture for all users and add-ons that are incompatible may no longer work. For this reason it is imperative that add-on authors update their add-ons to be compatible with the multi-process architecture.

Accessibility and touch screens

The next major multi-process update is scheduled for Firefox 51 when we’ll ship it to users with touchscreens, accessibility, and right to left browsers. That will conclude the first phase of our roll-out of the basic process separation that brings responsiveness to the Firefox UI, even when heavy pages are loading.

That’s not the end of our multi-process work. Not even close.

Multiple content processes

The second phase of this effort is to support multiple content processes. Where before we split content from UI so that pages loading wouldn’t slow down the UI, next up we’re splitting up the content processes so that one heavy page loading cannot slow down or hang pages loading in other tabs. This work is underway and should be available in the first half of 2017.

In parallel to work on multiple content processes, we’re also working on building a hardened sandbox for content processes. The goal for sandboxing is to restrict what access processes that host web content have to the browser and to the operating system. This will help secure Firefox against a range of potential exploits. If all goes well in testing, this work could see release this year.

Out of process add-ons

The final piece of this multi-process work will be to isolate extensions into their own sandboxed processes. Similar to how isolating and sandboxing web pages can help improve performance and prevent security exploits, putting extensions into their own process will make sure that an extension doesn’t slow down the browser or web pages and will help to prevent some classes of  attacks on Firefox that could happen through extensions. We’re still in the preliminary phase of this work.

This is a huge project that will take several more releases to complete but we’ve got a great foundation in place with the first phase shipping to end users now. We’ll build on that foundation to bring even more responsiveness and security to Firefox over the coming months without sacrificing the memory usage advantage we have over our competitors. Stay tuned to this and other Mozilla blogs for updates as the biggest architectural change in Firefox’s history rides the trains to release.

Reducing Adobe Flash Usage in Firefox

Browser plugins, especially Flash, have enabled some of our favorite experiences on the Web, including videos and interactive content. But plugins often introduce stability, performance, and security issues for browsers. This is not a trade-off users should have to accept.

Mozilla and the Web as a whole have been taking steps to reduce the need for Flash content in everyday browsing. Starting in August, Firefox will block certain Flash content that is not essential to the user experience, while continuing to support legacy Flash content. These and future changes will bring Firefox users enhanced security, improved battery life, faster page load, and better browser responsiveness.

Over the past few years, Firefox has implemented Web APIs to replace functionality that was formerly provided only by plugins. This includes audio/video playback and streaming capabilities, clipboard integration, fast 2D and 3D graphics, WebSocket networking, and microphone/camera access. As websites have switched from Flash to other web technologies, the plugin crash rate in Firefox has dropped significantly:

Plugin crash rate in Firefox

Firefox will continue this trend by blocking specific Flash content invisible to users. This is expected to reduce Flash crashes and hangs by up to 10%. To minimize website compatibility problems, the changes are initially limited to a short, curated list of Flash content that can be replaced with HTML. We intend to add to this list over time.

Later this year, we plan to expand this list to include the use of Flash to check content viewability, a common practice to measure advertising. This will improve Firefox performance and device battery life. We will make this change at the same time Firefox implements the equivalent HTML Intersection Observer API (Firefox bug 1243846) and recommend that content producers currently using Flash to measure viewability adopt this new API as soon as it is available.

In 2017, Firefox will require click-to-activate approval from users before a website activates the Flash plugin for any content. Websites that currently use Flash or Silverlight for video or games should plan on adopting HTML technologies as soon as possible. Firefox currently supports encrypted video playback using Adobe Primetime and Google Widevine as alternatives to plugin video.

We continue to work closely with Adobe to deliver the best possible Flash experience for our users. Our engineering partnership has led to improvements in high-DPI support on Windows, enhanced sandboxing, and an accelerated Flash rendering pipeline that improves performance and stability.

These changes are part of our ongoing efforts to make browsing safer and faster without sacrificing the Web experiences our users love. As we announced last year, Firefox plans to drop support for all NPAPI plugins, except Flash, in March 2017. The next major Firefox ESR (Extended Support Release) release, also scheduled for March, will continue to support plugins such as Silverlight and Java until early 2018, for those users who need more time for their transition.

We are experimenting with many other features and improvements that will make Firefox an even more awesome platform for discovery and collaboration. We welcome your feedback and feature requests.

Update on Firefox support for OS X

Mozilla will end support for Firefox on OS X 10.6, 10.7, and 10.8 in August, 2016. At that time, Firefox will continue to function on these platforms but will no longer receive new feature or security updates.

Firefox Extended Support Release (ESR) 45 will continue to support OS X 10.6, 10.7, and 10.8 until mid-2017, but this ESR release will be the last that supports them.

All three of these versions are no longer supported by Apple. Mozilla strongly encourages our users to upgrade to a version of OS X currently supported by Apple. Unsupported operating systems receive no security updates, have known exploits, and are dangerous for you to use.

What’s New in Firefox Beta

Today’s beta release of Firefox features a tool to view the open tabs that are synced across your desktop and mobile instances of Firefox.

Updates to Firefox for Android focus on a set of design changes that will make browsing safer and simpler for our users.

More information:

Firefox is the default browser for Linux users on Ubuntu, new snap format coming soon

At Mozilla, we strive to offer users a great experience based on transparency, choice and trust, and to make Firefox available across many platforms, devices and operating systems. Today, Mozilla and Canonical are renewing their partnership to make Firefox the default browser for Ubuntu users. We are proud to have been a partner of choice for Ubuntu for over a decade. Canonical and Mozilla share a similar heritage as open-source and community-supported organizations.

Ubuntu version 16.04 will include the introduction of the snap infrastructure. With the snap format, we will be able to continually optimize Firefox on Ubuntu. Like our rapid engineering release cycle, snap format will allow us to provide Linux users the most up-to-date features, in particular security patches, even after major Operating System ship dates.

Previously, a static version of Firefox would ship with each new Operating System version for the lifecycle of that OS. With the snap format, new features can be released to users of older OS versions too. Later this year, we will offer Firefox in snap format making it easier to push the browser directly to users rather than relying on an intermediary to accept updates before they reach users.

Mozilla To Test Widevine CDM in Firefox Nightly

Update, June 7, 2016: Support for Widevine is now available in the general Firefox release.

Update, April 27, 2016: Today, we will expand support of Widevine to our general release channel beginning in Firefox 47.

As we previously announced, Mozilla has been working to enable playback of HTML5 video content that requires DRM. Last year, we launched with Adobe’s Primetime CDM and now we will soon be testing Firefox support for Google’s Widevine CDM on Windows and Mac OS X. Firefox will download the CDM shortly after users first run Firefox after installing or upgrading. The CDM will be activated when users first interact with a site that uses Widevine.

Widevine support is an alternative solution for streaming services that currently rely on Silverlight for playback of DRM-protected video content. It will allow websites to show DRM-protected video content in Firefox without the use of NPAPI plugins. This is an important step on Mozilla’s roadmap to remove NPAPI plugin support.

The Widevine CDM runs in an open-source CDM sandbox in Firefox, providing better user security than NPAPI plugins.

For more information:

Shipping Some Firefox Features Outside of the Release Cycle

Four years ago, we updated the Firefox release process to the Train Model to move at the speed of the Web. More recently we improved the process further. We are now adding a mechanism to ship some features in Firefox even faster. This means it will take even less time for Firefox innovation and improvements to reach users.

Some features will now be shipped between release cycles, starting with Firefox Hello Beta. These modules are built into Firefox and delivered similarly to add-ons. This allows them to be updated more-frequently than the standard Firefox Rapid Release cycle.

This won’t interfere with our release cycle, which will still be used for most significant updates and users will only notice that some features, like Hello, are updated more frequently.

This is part of our ongoing commitment to continue delivering uncompromised quality in Firefox.

Viewing Cached Tabs Offline Ready for Testing in Firefox for Android Beta

We are testing a feature in Firefox for Android Beta that will display some Web pages even when you’re offline.

Firefox Android Beta Cached Tabs Viewing

If you’ve recently visited a site and it is still cached in the offline storage on your device, Firefox for Android Beta will display the stored offline version of the page instead of showing you an error. There’s no need to do anything to try this feature. You’ll notice that some pages you visit when you’re offline will still be displayed in Firefox for Android Beta, even when you aren’t connected to the Internet.

More information: