Firefox 149.0 is out with Side-by-Side Split View & Tab Notes

Firefox 149.0, the March release of this free open-source web browser, is available to download.

The new version introduced some exciting new features, improvements for Linux, and many changes for web developers.

Like Chrome/Chromium, Firefox now supports split view that displays two web pages side-by-side in single window, making easy to compare information or work across two pages at once.

To create a split view, either use Ctrl + Click to select two tabs, then right-click and choose “Open in Split View“, or, right-click on a tab and select “Add Split View“, which will resize the selected tab to left half, and list all other tabs in right allowing to choose one to display side-by-side.

Same to common tabs, you may switch between the split view tabs and change the URL in address bar to go to other websites. To exit split view, either right-click on tab and select “Separate Split View” or simply close one of the tabs.

Firefox 149 also introduced new experimental tab notes feature. With it, you can add a short note to a web-page to help remember why you opened tab page, what you planned to do next or any other information about the page.

The feature is available in Settings -> Firefox Labs. After enabled it, simply right-click on a tab and select “Add Note” menu option. It will pop-up a small dialog allowing to input something.

After that, it will display a small note icon in the tab, and move mouse cursor over that icon will show you the note via tool-tip.

All added notes will be there even after you closed the sites and re-open them, until you delete them via “Update Note -> Delete Note” context menu option or switch to another profile.

For Linux user, the new 149.0 version finally default to the XDG portal file picker if available, instead of using the GTK3 one. So that, it will be well integrated by trying to use your desktop native file chooser dialog.

Firefox now try to use Linux native file chooser

For Windows and macOS, user can now add a share button to the toolbar via “Customize toolbar” page, making easy to share a page using system sharing options.

Firefox 149 now provides a free built-in VPN for users who logged in via Mozilla account. With it, you can hide your location and IP address by routing it through a secure proxy when browsing the web.

It provides 50 GB of protection every month, and allows to turn the VPN on or off for specific websites. However, this is a progressive rollout feature at the moment only available in the US, UK, Germany and France.

This version also features some security improvements. It now automatically blocks notifications and permanently revokes permissions for any website flagged as malicious by SafeBrowsing.

It as well introduced a new new TrustPanel, that can be accessed through the shield icon in the address bar. It combines the previous active blocking protection and security status into new redesigned interface to check the privacy and security of the current page.

Other changes in Firefox 149 include:

• New redesigned error page.
• Hardware acceleration support for PDF loading.
• Enable auto-fill for users in Australia, India, Italy, Poland and Austria.
• On-device translation support for Bosnian, Norwegian Bokmål, Serbian and Thai.
• Use Windows.Devices.Geolocation API for geolocation in Windows.
• Various security fixes and API changes.

Get Firefox 149.0

The official release note will be available soon via the link below, while, this post is written according to the Github releases page.

Firefox 149 Release Note

For Linux, Windows, and macOS, the official installers as well as the source tarball are available to download at Mozilla website via this page.

And, Ubuntu since 22.04 with the pre-installed Firefox snap package will automatically update to the version 149.0 soon.

source https://ubuntuhandbook.org/index.php/2026/03/firefox-149-0-split-view-tab-note/