Mozilla Extends Firefox ESR 115 Support for Legacy Operating Systems Until March 2026

Mozilla has announced an extension of support for Firefox Extended Support Release (ESR) 115, allowing users on older operating systems—specifically Windows 7, Windows 8, Windows 8.1, and macOS versions 10.12 (Sierra) through 10.14 (Mojave)—to continue receiving critical security updates until March 2026. This decision marks the third extension of support for these legacy systems, which was initially set to expire in September 2024, then pushed to April 2025, and subsequently to September 2025 before the latest extension.

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Mozilla's ongoing support contrasts sharply with other major browser vendors like Google and Microsoft, who have ceased support for these older operating systems. According to Mozilla engineer Ryan VanderMeulen, the organization aims to reduce forced obsolescence by providing updates long after official vendor support has ended. This extension allows users who cannot upgrade their systems due to hardware limitations to maintain a secure browsing experience.

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The latest Firefox Public Data Report indicates that approximately 6.769% of Firefox users are still operating on Windows 7, highlighting the relevance of this support extension. Mozilla's decision to continue updates for Firefox ESR 115 is seen as a response to the needs of users who rely on outdated systems, particularly in enterprise environments and regions with hardware constraints.

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While Mozilla recommends users transition to supported operating systems to access newer features and ensure long-term stability, the extension provides a crucial safety net for those unable to do so.

Mozilla Extends Firefox ESR 115 Support for Windows 7 Until March 2026

Despite the positive reception from some users, there has been criticism regarding Mozilla's decision to integrate AI features, including Microsoft Copilot, into Firefox. The community has expressed concerns over privacy and performance issues associated with AI tools. Previous AI features in Firefox have led to complaints about CPU spikes and battery drain, prompting Mozilla to address these concerns.

Firefox Nightly now lets you access Microsoft Copilot from the sidebar

The introduction of Microsoft Copilot in Firefox Nightly has received mixed reactions. While some users appreciate the convenience of having AI tools readily accessible, others remain skeptical about the implications of embedding such features directly into the browser.

Firefox Adds Microsoft Copilot AI to Its Sidebar — But Will Users Accept It?

Mozilla has stated that the decision to extend support for Firefox ESR 115 will be reevaluated in February 2026, with any further updates to the end-of-life timeline to be announced at that time. The organization emphasizes its commitment to user agency and security, particularly for those on legacy systems.

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As Mozilla continues to navigate the balance between innovation and user needs, the future of Firefox ESR 115 remains uncertain beyond March 2026. The company is expected to monitor user feedback closely and may adjust its strategies based on community responses to both the support extensions and the integration of AI features.

Mozilla Extends Firefox ESR 115 Support for Windows 7 Until March 2026