Mozilla has officially released Firefox 153, bringing another round of improvements to its open-source web browser. The latest version introduces new multimedia capabilities, enhanced PDF editing tools, stronger privacy protections, better support for modern web technologies, and several features aimed at improving the browsing experience across Linux, Windows, and macOS. Firefox 153 became available on the stable release channel on July 21, 2026.

While this isn’t a major redesign, Firefox 153 delivers a collection of practical updates that benefit both everyday users and web developers.

HDR Video Playback Comes to Windows

One of the headline features in Firefox 153 is support for High Dynamic Range (HDR) video playback on compatible Windows systems.

Users with HDR-capable displays and Windows HDR enabled can now enjoy richer colors, improved contrast, and brighter highlights when watching supported online video content. Mozilla notes that certain laptop displays offering only “HDR video streaming” are not currently supported, and some HDR videos recorded on mobile phones may still have limitations.

Although this feature is Windows-specific, it represents another step toward bringing Firefox in line with modern multimedia standards.

PDF Editing Becomes Even More Powerful

Mozilla continues expanding Firefox’s built-in PDF editor, eliminating the need for third-party applications in many situations.

Firefox 153 introduces the ability to:

• Merge multiple PDF documents
• Insert images as new PDF pages
• Continue using existing editing tools such as annotations, page organization, and text editing

These additions make Firefox an even more capable document viewer and editor, especially for users who frequently work with PDF files.

Stronger Privacy and Permission Controls

Privacy remains one of Firefox’s biggest selling points, and version 153 introduces several enhancements designed to give users more visibility and control over website permissions.

New improvements include:

• A visual indicator when a website is actively accessing your location
• More restrictive default permissions for browser extensions accessing local files
• Local Area Network (LAN) restrictions enabled by default for all users

These changes reduce unnecessary exposure of local resources while making it easier to understand what websites and extensions can access.

Experimental JPEG XL Support

Firefox 153 also adds experimental support for the JPEG XL image format, which many developers consider a promising successor to older image standards.

JPEG XL offers several advantages, including: