Firefox Sidebar and Vertical tabs: try them out in Nightly Firefox Labs 131

We are excited to share that vertical tabs and a new sidebar experience are now available in Nightly 131. This update has been highly anticipated and requested by the community, and we are looking forward to seeing how it enhances your browsing and productivity. To give this in-progress work a try:

• update to the latest Nightly,
• go to Settings > Firefox Labs,
• activate Sidebar and Vertical tabs experiments,
• click Customize toolbar in the toolbar right-click menu, and drag the sidebar icon to your toolbar. Clicking on the sidebar icon will allow you to expand vertical tabs.

We have designed the new sidebar and vertical tabs experience to make two core browsing workflows more seamless – context-switching and multitasking.

• The new sidebar allows you to quickly cross-reference all of your favorite tools – be it tabs on your mobile phone, your favorite extension, or bookmarks with your main task at hand.
• Vertical tabs make it easier to scan information and switch between tasks.

This work is still very much in progress. You’ll see us refine things in the coming months, and we appreciate your feedback to help bring these features to life.

We will also be sharing our backlog of improvements on Mozilla Connect, so you can get a sense for where we ultimately want these features to be.

What’s Next? 

We’re calling on our community to test the new sidebar and vertical tabs experience and your constructive feedback is crucial as we refine these features. Please share your thoughts on Mozilla Connect – we take your input into account and it helps us create a browsing experience that meets your needs 🦊.

If you’re a web extension developer and your extension uses sidebar APIs or works with tabs, we’d love you to test it with the new sidebar and vertical tabs enabled. While there are no changes to Web Extension APIs tied to these features, this is a good opportunity to anticipate unforeseen issues resulting from the updated UI.