Open-source alternatives to Firefox

8 genuinely open-source alternatives. The projects are compared by license, workflow, self-hosting, and pricing.

Why look for a Firefox alternative?

Firefox is an open-source browser known for Gecko, privacy features, extensions, synchronization, and independence from Chromium. People look for alternatives when they want stronger privacy defaults, deeper customization, Chromium compatibility, fewer integrated services, or a browser engine independent from both Chromium and Gecko.

Ladybird

Independent open-source browser engine and browser.

Ladybird is a BSD-2-Clause browser built around an independent engine, developed without Chromium, WebKit, or Gecko dependencies by a nonprofit initiative.

BSD-2-ClauseSelf-hosted

Pricing: Free and open source; early-stage development builds are evolving.

Independent engine
No Chromium or Gecko dependency
Nonprofit-backed open-web focus
Early in development
Website compatibility is evolving
Smaller contributor ecosystem

View on GitHub

Zen Browser

Customizable Firefox-based browser with vertical tabs and workspaces.

Zen Browser is an MPL-2.0 Firefox-based browser focused on vertical tabs, split views, workspaces, compact layouts, privacy, and extensive interface customization.

MPL-2.0Self-hosted

Pricing: Free and open source under MPL-2.0.

Vertical tabs and workspaces
Firefox extension compatibility
Strong customization and productivity features
Younger project
Smaller community
Depends on Mozilla's Gecko engine

View on GitHub

Helium

Minimal privacy-focused Chromium browser.

Helium is a GPL-3.0 Chromium-based browser focused on privacy and simplicity, with built-in ad and tracker blocking, fingerprinting protection, HTTPS enforcement, and reduced Google integrations.

GPL-3.0 plus upstream licensesSelf-hosted

Pricing: Free and open source; upstream Chromium components retain their respective licenses.

Chromium compatibility and Chrome extensions
Built-in ad/tracker blocking
Minimal interface and no analytics focus
Still Chromium-based
Beta-stage project
No built-in sync by design

View on GitHub

Brave

Mature Chromium browser with built-in privacy protections.

Brave is an MPL-2.0 Chromium-based browser with built-in blocking for ads, trackers, cookies, and fingerprinting, plus synchronization, mobile apps, and Chrome extension compatibility.

MPL-2.0Self-hosted

Pricing: Free and open source; optional Brave services may have separate terms.

Mature browser
Built-in ad/tracker blocking
Chrome compatibility, sync, and mobile apps
Chromium-based
Includes optional integrated Brave services
Less engine diversity than Gecko alternatives

View on GitHub

Waterfox

Privacy-focused Firefox fork with fewer Mozilla services.

Waterfox is an MPL-2.0 Firefox-based browser with reduced telemetry, built-in content blocking, private containers, privacy-focused DNS features, and Firefox extension compatibility.

MPL-2.0Self-hosted

Pricing: Free and open source under MPL-2.0; hosted services may be offered separately.

Firefox/Gecko foundation
Reduced telemetry and private containers
Firefox extension compatibility
Depends on Firefox upstream
Smaller community than Firefox
Less hardened than LibreWolf in some areas

View on GitHub

LibreWolf

Hardened Firefox fork focused on privacy and security.

LibreWolf is an MPL-2.0 community Firefox fork that removes Mozilla telemetry and sponsored integrations, applies hardened privacy settings, and includes uBlock Origin by default.

MPL-2.0Self-hosted

Pricing: Free and open source under MPL-2.0.

Strong privacy defaults
No Mozilla telemetry or sponsored content
uBlock Origin and fingerprinting resistance
Hardened settings can break websites
DRM disabled by default
Less convenient built-in sync

View on GitHub

Flow

Open-source Chromium browser with spaces and command palette.

Flow is a GPL-3.0 Chromium browser focused on productivity, spaces, profiles, sidebar navigation, a command palette, and Chrome extension support.

GPL-3.0Self-hosted

Pricing: Free and open source under GPL-3.0.

Spaces and profiles
Command palette and sidebar navigation
Chrome extensions and open development
Younger project
Chromium-based
Privacy features are still evolving

View on GitHub

Midori Browser

Lightweight privacy browser derived from Firefox technology.

Modern Midori is an MPL-2.0 lightweight browser focused on privacy, tracker blocking, workspaces, customization, and cross-platform availability on a Firefox-derived foundation.

MPL-2.0Self-hosted

Pricing: Free and open source under MPL-2.0.

Lightweight approach
Firefox-derived engine
Tracker blocking, workspaces, and customization
Smaller ecosystem
Architecture has changed over time
Less mature than Firefox

View on GitHub

Compare Firefox alternatives

Tool	Stars	License	Self-hosted	Pricing
Ladybird	—	BSD-2-Clause	Yes	Free and open source; early-stage development builds are evolving.
Zen Browser	—	MPL-2.0	Yes	Free and open source under MPL-2.0.
Helium	—	GPL-3.0 plus upstream licenses	Yes	Free and open source; upstream Chromium components retain their respective licenses.
Brave	—	MPL-2.0	Yes	Free and open source; optional Brave services may have separate terms.
Waterfox	—	MPL-2.0	Yes	Free and open source under MPL-2.0; hosted services may be offered separately.
LibreWolf	—	MPL-2.0	Yes	Free and open source under MPL-2.0.
Flow	—	GPL-3.0	Yes	Free and open source under GPL-3.0.
Midori Browser	—	MPL-2.0	Yes	Free and open source under MPL-2.0.

Which one should you choose?

Want the strongest Firefox-based privacy defaults

LibreWolf removes Mozilla telemetry and sponsored integrations while applying hardened privacy settings and shipping uBlock Origin by default.

LibreWolf

Want a modern customizable Firefox experience

Zen adds vertical tabs, split views, workspaces, compact layouts, and extensive UI customization on top of Gecko.

Zen Browser

Want Chrome extension and website compatibility

Brave uses Chromium, includes built-in ad and tracker blocking, and offers strong compatibility with Chrome extensions and websites.

Brave

Want an independent browser engine

Ladybird is building a new browser engine rather than relying on Chromium, Gecko, or WebKit.

Ladybird

Want Firefox with fewer Mozilla services

Waterfox keeps the Firefox-derived foundation while reducing telemetry and adding privacy and productivity features.

Waterfox

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