Thank you, contributors!

As a large, complex, and heavily visited site, it can be challenge for our small team to make sure that extension users and developers have a good experience on (AMO). Fortunately, we are not alone. Thanks to volunteer contributors who share their time, energy, and talent, we’re able to extend our ability to extend the web by fixing reported bugs, implementing routine updates, landing new features, and moderating content listed on AMO.

We’d like to acknowledge and thank the following community members for their contributions to AMO from April – June 2018. (AMO)

Last quarter, 19 community members submitted 68 patches to fix a variety of frontend and backend issues on AMO, like removing obsolete code, keeping the content on the Developer Hub up-to-date, making it easier for users to rate add-ons, and making sure the user interface stays tidy. Many thanks to community members Biskit1, Ankush Chadda, Deepanshu Jain, Dominic Lee, gabbyjose, Lavish Aggarwal, Manish Devgan,  Piyush Mittal, Raffaele Spinelli, Revi, Sanyam Khurana, Sean Prashad, Shivam Singhal, Svitlana Galianova, Swarnava Sengupta, Trishul Goel, TwinProduction, Vimal Raghubir, and xu3u4 for their code contributions to improve AMO!

Extension & Theme Reviewers

No one enjoys coming across spam or unsavory themes while browsing AMO, or installing an extension that comes with a nasty surprise (like compromising user security). Our team of volunteer reviewers helps ensure that users have a good experience on AMO by moderating extensions and themes to make sure they comply with our Acceptable Use Policy and Add-on Policies.

We would like to extend a special thanks to this quarter’s top reviewers: erosman, rctgamer3, Ett Chung, B.J. Herbison, Jyotsna Gupta, happy-ferret, Pam, and candelora for their exceptional contributions to the review process during the last few months.

Community members contribute in many other ways to keep the add-ons ecosystem vibrant and strong. To learn more about these contributions, please visit our recognition wiki. To get involved, wiki for current contribution opportunities!

The New Thunderbird Add-ons Site is Now Live

As we announced last week,  SeaMonkey and Thunderbird add-ons will now reside on Add-ons for Firefox and Firefox for Android will remain on (AMO). We wanted to let you know that the split is now done and the new site is live.

If you run into any issues on the new site, you can file them here. For AMO, use this link instead. We’ve also set up an FAQ on the Mozilla Wiki explaining the reasons behind this move and providing some guidance for people looking for help on it.

No Longer Lost in Translation

9 popular extensions in 7 new locales


You might have noticed that while Firefox supports 90 languages, many extensions and their listings on (AMO) are only available in English.

At present, we don’t have a way to connect extension developers with the translation community at scale, and  Pontoon, Mozilla’s tool for localizing products and websites, currently only supports translating the AMO site itself.

What we do have, however, is a desire to make translation resources available, a longstanding and active community of localizers, and friends on Mozilla’s Open Innovation team who specialize in putting the two together. Part of Open Innovation’s work is to explore new ways to connect communities of enthusiastic non-coding contributors to meaningful projects within Mozilla. Together with Rubén Martín, we ran a campaign to localize an initial group of top Firefox extensions into the 7 most popular languages of Firefox users.

More than 100 multilingual Mozillians answered the call for participation and submitted more than 140,000 translated words for these extensions using CrowdIn, a localization platform most recently used for Mozilla’s Common Voice project. These translations were reviewed by a core team of experienced localizers, who then provided approved translations to developers involved in the campaign to include in their next version update.

Now, you can enjoy this collection of extensions in Chinese (simplified), Dutch, French, German, Italian, Portuguese (Brazilian),  and Spanish:

1-Click Youtube Download* · Adblock for Firefox · Download Flash and Video
Greasemonkey · New Tab Override · NoScript Security Suite
Pinterest Save Button · signTextJS plus · To Google Translate

While this campaign is limited to a small group of extensions, we hope to roll out a localization process for all interested extension developers in the near future. Stay tuned for more information!

If you would like to participate in future campaigns at Mozilla, subscribe to Mission-Mozillians-Campaigns tag on Discourse to learn how to get involved. If you are specifically interested in localizing other content for Mozilla, check out the L10n wiki to learn how to get started.

Many thanks to the extension developers and localizers who participated in this campaign.

* Coming soon! If you would like a localized version of this extension in one of the languages listed above, install the extension now. During its next update, you will be automatically switched to the version for your locale.

Upcoming changes for themes

Theming capabilities on (AMO) will undergo significant changes in the coming weeks. We will be switching to a new theme technology that will give designers more flexibility to create their themes. It includes support for multiple background images, and styling of toolbars and tabs. We will migrate all existing themes to this new format, and their users should not notice any changes.

As part of this upgrade, we need to remove the theme preview feature on AMO. This feature allowed you to hover over the theme image and see it applied on your browser toolbar. It doesn’t work very reliably because image sizes and network speed can make it slow and unpredictable.

Given that the new themes are potentially more complex, the user experience is likely to worsen. Thus, we decided to drop this in favor of a simpler install and uninstall experience (which is also coming soon). The preview feature will be disabled starting today.

It’s only a matter of weeks before we release the new theme format on AMO. Keep following this blog for that announcement.

New Site for Thunderbird and SeaMonkey Add-ons

When Firefox Quantum (version 57) launched in November 2017, it exclusively supported add-ons built using WebExtensions APIs. (AMO) has followed a parallel development path to Firefox and will soon only support WebExtensions-based add-ons.

As Thunderbird and SeaMonkey do not plan to fully switch over to the WebExtensions API in the near future, the Thunderbird Council has agreed to host and manage a new site for Thunderbird and SeaMonkey add-ons. This new site,, will go live in July 2018.

Starting on July 12th, all add-ons that support Thunderbird and SeaMonkey will be automatically ported to The update URLs of these add-ons will be redirected from AMO to the new site and all users will continue to receive automatic updates. Developer accounts will also be ported and developers will be able to log in and manage their listings on the new site.

Thunderbird or SeaMonkey add-ons that also support Firefox or Firefox for Android will remain listed on AMO.

If you come across any issues or need support during the migration, please post to this thread in our community forum.

Extensions in Firefox 62

Last week Firefox 62 moved into the Beta channel. This version has fewer additions and changes to the WebExtensions API than the last several releases. Part of that is due to the maturing nature of the API as we get farther away from the WebExtension API cutover back in release 57, now over seven months ago. Part of it was a focus on cleaning up some internal features — code changes that increase the maintainability of Firefox but are not visible to external developers. And, let’s be honest, part of it is the arrival of summer in the Northern hemisphere, resulting in happy people taking time to enjoy life outside of browser development.

User Interface Improvements

Extensions with a toolbar button (browser action) can now be managed directly from the context menu of the button.  This is very similar to the behavior with page actions – simply right click on the toolbar button for an extension and select Manage Extension from the context menu.  This will take you to the extension’s page in about:addons.

Manage Extension Context Menu

You can now manage hidden tabs, introduced in Firefox 61, via a down-arrow that is added to the end of the tab strip. When clicked, this icon will show all of your tabs, hidden and visible.  Firefox 62 introduces a new way get to that same menu via the History item on the menu bar. If you have hidden tabs and select the History menu, it will display a submenu item called “Hidden Tabs.”  Selecting that will take you to the normal hidden tabs menu panel.

Hidden Tabs Menu

API Improvements

A few enhancements to the WebExtensions API are now available in Firefox 62, including:

Theme Improvements

A couple of changes to the WebExtensions theme API landed in this release:

Tab Background Separator

Bug Fixes

A few noticeable bug fixes landed in Firefox release 62, including:

Thank You

A total of 48 features and improvements landed as part of Firefox 62. As always, a sincere thank you to every contributor for this release, especially our community volunteers including Tim Nguyen, Jörg Knobloch, Oriol Brufau, and Tomislav Jovanovic. It is only through the combined efforts of Mozilla and our amazing community that we can ensure continued access to the open web. If you are interested in contributing to the WebExtensions ecosystem, please take a look at our wiki.


July’s Featured Extensions

Firefox Logo on blue background

Pick of the Month: Midnight Lizard

by Pavel Agarkov
More than just dark mode, Midnight Lizard lets you customize the readability of the web in granular detail—adjust everything from color schemes to lighting contrast.

“This has got to be the best dark mode add-on out there, how is this not more popular? 10/10”

Featured: Black Menu for Google

by Carlos Jeurissen
Enjoy easy access to Google services like Search, Translate, Google+, and more without leaving the webpage you’re on.

“Awesome! Makes doing quick tasks with any Google app faster and simpler!”

Featured: Authenticator

by mymindstorm
Add an extra layer of security by generating two-step verification codes in Firefox.

“Thank you so much for making this. I would not be able to use many websites without it now days, literally, since I don’t use a smartphone. Thank you thank you thank you. Works wonderfully.”

Featured: Turbo Download Manager

by InBasic
A download manager with multi-threading support.

“One of the best.”

Featured: IP Address and Domain Information

by webdev7
Know the web you travel! See detailed information about every IP address, domain, and provider you encounter in the digital wild.

“The site provides valuable information and is a tool well worth having.”

If you’d like to nominate an extension for featuring, please send it to amo-featured [at] mozilla [dot] org for the board’s consideration. We welcome you to submit your own add-on!

Larger image support on

Last week, we pushed an update that enables add-on developers to use larger image sizes on their add-on listings.

We hadn’t updated our size limits for many years, so the images on listing pages are fairly small. The image viewer on the new website design scales the screenshots to fit the viewport, which makes these limitations even more obvious.

For example, look at this old listing of mine.

Old listing image on new site

The image view on the new site. Everything in this screenshot is old.

The image below better reflects how the magnified screenshot looks like on my browser tab.

All of the pixels


After this fix, developers can upload images as large as they prefer. The maximum image display size on the site is 1280×800 pixels, which is what we recommend they upload. For other image sizes we recommend using the 1.6:1 ratio. If you want to update your listings to take advantage of larger image sizes, you might want to consider using these tips to give your listing a makeover to attract more users.

We look forward to beautiful, crisper images on add-on listing pages.

Add-ons at the San Francisco All Hands Meeting

Last week, more than 1,200 Mozillians from around the globe converged on San Francisco, California, for Mozilla’s biannual All Hands meeting to celebrate recent successes, learn more about products from around the company, and collaborate on projects currently in flight.

For the add-ons team, this meant discussing tooling improvements for extension developers, reviewing upcoming changes to (AMO), sharing what’s in store for the WebExtensions API, and checking in on initiatives that help users discover extensions. Here are some highlights:

Developer Tools

During a recent survey, participating extension developers noted two stand-out tools for development: web-ext, a command line tool that can run, lint, package, and sign an extension; and about:debugging, a page where developers can temporarily install their extensions for manual testing. There are improvements coming to both of these tools in the coming months.

In the immediate future, we want to add a feature to web-ext that would let developers submit their extensions to AMO. Our ability to add this feature is currently blocked by how AMO handles extension metadata. Once that issue is resolved, you can expect to see web-ext support a submit command. We also discussed implementing a create command that would generate a standard extension template for developers to start from.

Developers can currently test their extensions manually by installing them through about:debugging. Unfortunately, these installations do not persist once the browser is closed or restarted. Making these installations persistent is on our radar, and now that we are back from the All Hands, we will be looking at developing a plan and finding resources for implementation. (AMO)

During the next three months, the AMO engineering team will prioritize work around improving user rating and review flows, improving the code review tools for add-on reviewers, and converting dictionaries to WebExtensions.

Engineers will also tackle a project to ensure that users who download Firefox because they want to install a particular extension or theme from AMO are able to successfully complete the installation process. Currently, users who download Firefox from a listing on AMO are not returned to AMO when they start Firefox for the first time, making it hard for them to finish installing the extension they want. By closing this loop, we expect to see an increase in extension and/or theme installations.

WebExtensions APIs

Several new and enhanced APIs have landed in Firefox since January, and more are on their way. In the next six months, we anticipate landing WebExtensions APIs for clipboard support, bookmarks and session management (including bookmark tags and further expansions of the theming API).

Additionally, we’ll be working towards supporting visual overlays (like notification bars, floating panels, popups, and toolbars) by the end of the year.

Help Users Find Great Extensions Faster

This year, we are focusing on helping Firefox users find and discover great extensions quickly. We have made a few bets on how we can better meet user needs by recommending specific add-ons. In San Francisco, we checked in on the status of projects currently underway:

Recommending extensions to users on AMO

In May, we started testing recommendations on listing pages for extensions commonly co-installed by other users.

A screenshot of the recommender feature on AMO.

Results so far have shown that people are discovering and installing more relevant extensions from these recommendations than the control group, who only sees generally popular extensions. We will continue to make refinements and fully graduate it into AMO in the second half of the year.

(For our privacy-minded friends: you can learn more about how Firefox uses data to improve its products by reading the Firefox Privacy Notice.)

Adding extensions to the onboarding tour for new Firefox users.

We want to make users aware of the benefits of customizing their browser soon after installing Firefox. We’re currently testing a few prototypes of a new onboarding flow.

And more!

We have more projects to improve extension discovery and user satisfaction on our Trello.

Join Us

Are you interested in contributing to the add-ons ecosystem? Check out our wiki to see a list of current contribution opportunities.


June’s Featured Extensions

Firefox Logo on blue background

Pick of the Month: Tabliss

Enjoy a gorgeous new tab page with customizable background images and many informational widgets to choose from, like local weather, date/time, bookmarks, and more.

“Wow. Absolutely stunning without the need for advanced user input to make it stunning.”

Featured: View Page Archive & Cache

by Armin Sebastian
Find archived and cached versions of older web pages with the help of multiple search engines, like Wayback Machine, Google Cache, Bing Cache, and others.

“Outstanding! Often have to search multiple sites for cached pages. Very useful time-saver for me. Thank you!”

Featured: Share Backported

by Daniele Mte90 Scasciafratte
Older versions of Firefox included a social media ‘share’ button in the Toolbar. This extension brings it back to its original glory.

“Beautifully implemented!”

If you’d like to nominate an extension for featuring, please send it to amo-featured [at] mozilla [dot] org for the board’s consideration. We welcome you to submit your own add-on!