Firefox 153.0 is Out with Native Containers & AI Assistant

Firefox 153.0, the new monthly release of this popular free open-source web browser, is finally available to download.

The new version is available after 3 more Beta testing releases, features native containers support, HDR video playback for Windows, and more security improvements.

User can now right-click or long press New Tab (the plus icon) button or right-click on a link and choose to open new tab in container. In the case, your browsing data in that tab will be stored in an isolated environment.

Meaning you can use different accounts in the same website and limit cross-site tracking, by opening multiple tabs in different containers with separate cookies.

open new tab in container

This version also extended PDF editing support. It now supports merging multiple PDFs by dragging a PDF in the PDF sidebar. And, user can now add images as new pages within PDFs using the PDF editor.

For Windows, the High Dynamic Range video playback is now available, though user needs the HDR mode enabled for the display in the Windows Settings -> Display. However, laptop displays that only offer “HDR video streaming” are not supported, and, some videos recorded on phones in certain orientations are currently not shown as HDR so far.

Firefox 153 introduced new AI-based browsing assistant feature called Smart Window. With it enabled, the new tab will be an AI chat box, with Google Gemini, Alibaba qwen, OpenAI GPT, as well as custom LLM models support.

The new smart window is a progressive roll-out feature that’s not available for all users. You may visit this page and log in with Firefox account to try it out.

This version also improved security support by enabling Local Network Access restrictions for all users. It now requires websites to request permission before connecting to devices on your local network or to apps and services on your device.

Extensions can no longer access local files by default, though user can grant or revoke this access with new setting options. And, whenever a website has access to your location, it now highlights the location permission icon in red.

Other changes include:

• Share open page via QR code.
• Add Pick Color quick action triggered from the address bar.
• Support Apple’s system-wide full-screen keyboard command (Globe-F).
• Verify and display Qualified Website Authentication Certificates.
• Access video actions from context menus.
• Remove outdated cookie settings.

For developers, there are as well new popover=hint spec, text import attribute to import text files, user agent Picture-In-Picture functionality, and more.

Get Firefox 153.0

More changes about Firefox 153.0 as well as the download link will be available in the link below soon:

Firefox 153.0

If you can’t wait, then go to ftp.mozilla.org/pub/firefox/releases/153.0 to get Firefox 153.0 package.

source https://ubuntuhandbook.org/index.php/2026/07/firefox-153-0-native-containers-ai-assistant/