Mozilla has begun releasing Firefox 145, introducing major enhancements to its anti-fingerprinting defenses that reduce the number of users who can be uniquely identified by tracking scripts by nearly 50%.

The update marks the second phase of Mozilla’s broader effort to counter covert tracking methods that operate independently of blocklists. Scheduled for full rollout on November 11, 2025, the improvements were outlined by Tom Ritter, Senior Security Engineer at Mozilla, who highlighted the company’s commitment to mitigating browser fingerprinting—an advanced tracking technique that profiles users based on system and behavioral characteristics such as hardware configuration, fonts, time zone, and graphic computation patterns. Fingerprinting is particularly invasive because it persists across sessions and often bypasses private browsing protections.

Figure 1. Firefox Version 145.

Building on protections introduced starting in 2021, Firefox 145 further restricts access to detailed system information commonly used to increase fingerprint uniqueness. Newly protected data points include CPU core counts, touchscreen support, and taskbar dimensions, making it significantly harder for trackers to distinguish one user from another.

Mozilla continues to position Firefox as a privacy-first browser aligned with its nonprofit mission. Existing features like Enhanced Tracking Protection (ETP), Total Cookie Protection, and fingerprinting resistance in Private Browsing and ETP Strict mode form the backbone of this layered strategy [1]. Mozilla plans to enable the protections by default pending additional testing to prevent resistance features from impairing legitimate functions such as video conferencing or time-dependent services. Figure 1 shows Firefox Version 145.

Additional Features in Firefox 145

Alongside privacy upgrades, Firefox 145 introduces:

• A redesigned PDF annotation tool with support for comment organization
• Enhanced tab group previews
• Updated UI styling featuring rounded tab layouts

The release also officially ends support for 32-bit Linux on x86, citing minimal usage and increasing maintenance demands, and advises users to transition to 64-bit distributions.

Firefox 145 will roll out to existing users starting tomorrow, with early access available now via Mozilla’s FTP download servers.

Reference:

1. https://cyberinsider.com/firefox-145-introduces-stronger-user-fingerprinting-protection/

Cite this article:

Keerthana S (2025), New Fingerprinting Resistance Measures Launched in Firefox Version 145, AnaTechMaz, pp.242