Google Chrome 
Firefox LibreWolf is a community-driven fork of Mozilla Firefox focused on privacy, security, and user freedom. First released on March 7, 2020 for Linux (with Windows and macOS following approximately one year later), LibreWolf applies over 500 privacy, security, and performance settings and patches on top of the latest Firefox stable source. There is no company behind LibreWolf — no legal entity, no central organization, and no commercial interests. Development takes place primarily on Codeberg (codeberg.org/librewolf) with 16 repositories, and is mirrored on GitLab and GitHub.
The project’s philosophy is privacy by design rather than privacy by policy. All Mozilla telemetry is completely removed — crash reports, Normandy experiments, studies, and personalized recommendations are disabled. Pocket integration, sponsored content, and sponsored shortcuts are all stripped out. LibreWolf does not phone home to Mozilla or any other server. The project states they do not collect any data and would not even have the infrastructure to do so.
LibreWolf does NOT accept donations. The maintainers explain they do not want administrative burden, do not want to become dependent on funding, and want contributors to be free to move on without obligations. The browser is distributed under the Mozilla Public License 2.0 and is explicitly NOT associated with Mozilla or its products.
Key Features
- All Telemetry Removed: Crash reports, Normandy, studies, and personalized recommendations completely disabled
- uBlock Origin Pre-installed: Default ad and tracker blocking out of the box
- resistFingerprinting Enabled: Including letterboxing for window size fingerprinting protection
- HTTPS-Only Mode: Enabled by default
- Total Cookie Protection: Cookie isolation (dFPI) enabled by default
- No Pocket, No Sponsored Content: All Mozilla commercial integrations stripped
- librewolf.overrides.cfg: Persistent user configuration file that survives updates
- Privacy-Only Search Engines: DuckDuckGo default, with Searx, MetaGer, Mojeek, and Startpage included
Privacy Highlights
LibreWolf implements privacy through code removal rather than settings toggles. All Mozilla telemetry code paths are removed — the browser simply does not contain the functionality to collect or transmit user data. Firefox’s privacy.resistFingerprinting is enabled by default, which includes letterboxing (padding the browser window to prevent size-based fingerprinting), timezone spoofing to UTC, restricted font access, and common version/OS string reporting.
Additional privacy hardening includes: HTTPS-Only Mode enabled, Total Cookie Protection (dFPI) for cookie isolation, referrer trimming, fingerprinting API blocking, DRM disabled by default, built-in PDF reader scripting disabled, IDN homograph attack protection, media autoplay disabled, search suggestions and URL bar ads disabled, and stricter TLS/SSL negotiation. Only privacy-respecting search engines are included — Google and Bing are not offered.
The librewolf.overrides.cfg file allows users to customize any settings using JavaScript syntax, and this configuration persists across updates. This provides a portable, reproducible privacy configuration.
Privacy Breakdown
Data Residency (Score: 90 — Confidence: High)
Pros:
- No data is collected or transmitted — there is nothing to reside anywhere.
- No central servers, no telemetry endpoints, no phoning home.
- As a desktop application with no server component, data residency concerns are minimal.
Cons:
- Browser updates and extension updates require network connections.
- DuckDuckGo (default search) is a US company.
- No legal entity to enforce data residency commitments.
Open Source (Score: 90 — Confidence: High)
Pros:
- Fully open source under MPL-2.0 (browser code) and AGPL-3.0 (website).
- Source code publicly available on Codeberg (codeberg.org/librewolf/source) and mirrored on GitLab.
- 16 repositories covering source, settings, platform-specific builds, and more.
- Built from the latest Firefox stable source — well-audited, widely reviewed upstream.
Cons:
- No independent security audit documented specifically for LibreWolf patches.
- Small volunteer contributor base compared to Firefox (funded by hundreds of millions in revenue).
- Sustainability concerns due to reliance on unpaid volunteers.
Privacy Policy (Score: 80 — Confidence: Medium)
Pros:
- Privacy by design — telemetry code physically removed, not just disabled.
- Zero data collection. Project states they would not even have infrastructure to collect data.
- Over 500 privacy settings and patches applied on top of Firefox.
Cons:
- No formal privacy policy document — privacy guarantee is architectural, not legal.
- No legal entity that can be held accountable for privacy commitments.
- Community project with no commercial incentive to maintain specific privacy guarantees.
Trackers (Score: 99 — Confidence: High)
Pros:
- Zero trackers, zero telemetry, zero analytics. All telemetry code removed at source level.
- uBlock Origin pre-installed by default.
resistFingerprintingenabled by default with letterboxing.- No Pocket integration, no sponsored content, no Mozilla experiments.
Cons:
- DuckDuckGo (default search engine) operates its own ad network.
- Extension updates require connections to Mozilla infrastructure.
- 1 point deducted for default search engine being US-based.
Terms of Service (Score: 70 — Confidence: Medium)
Pros:
- MPL-2.0 license grants user freedom to use, modify, and distribute.
- No registration required. No account means no termination concerns.
Cons:
- No formal Terms of Service document.
- No legal entity to hold accountable for service quality or privacy guarantees.
- No user guarantees, service level agreements, or dispute resolution.
Controversies
The most frequently cited concern is LibreWolf’s lack of built-in automatic updates. Users must rely on package managers or manually update. On Windows, a separate “LibreWolf WinUpdater” package is offered. Security patches from Firefox may be delayed if users do not promptly update, though updates usually arrive within three days of each upstream Firefox stable release, sometimes same-day. [1]
LibreWolf disables Google Safe Browsing, citing censorship concerns and the practical issue that Safe Browsing requires a Google developer key at build time. Mozilla’s implementation is acknowledged as privacy-respecting, so disabling it represents a genuine security trade-off. [2]
LibreWolf is not recommended by Privacy Guides, primarily due to the auto-update concern and the small team size. Privacy Guides prefers browsers with robust auto-update mechanisms to ensure users receive security patches promptly. [3]
