Mozilla Firefox 153.0 Release Notes & Changelog

Mozilla Firefox 153.0

Get release alerts

152.0.6→153.0SecurityFeatureBug fixPerformance

📅 July 21, 2026🗂 Browsers📦 Mozilla Firefox ↗📜 Full changelog ↗

✦ Editor's summary

Firefox 153.0 introduces new browser features, performance optimizations, web platform improvements, and multiple security fixes. The release also includes developer enhancements, compatibility updates, and stability improvements across supported desktop platforms.

⚠ Security impact

Fixed multiple security vulnerabilities, including memory safety issues identified through internal audits and external security research.
Resolved vulnerabilities affecting web content processing and browser isolation mechanisms.
Updated bundled third-party libraries to address known security issues where applicable.

What's new

Introduced new browser features and user experience improvements.
Improved overall browser performance and page responsiveness.
Enhanced compatibility with modern web standards and APIs.
Updated Developer Tools with debugging and inspection improvements.
Fixed multiple stability issues and browser crashes.
Resolved compatibility issues affecting websites and web applications.
Included various security fixes and platform updates.

💬 Comments (0)

Have you installed this Mozilla Firefox update?

Share any installation issues, compatibility changes, or fixes you noticed.