Umbra Browser
Privacy that doesn't break the web
A Firefox ESR fork built for people who want strong privacy without losing access to streaming services, banking sites, or everyday browsing. Choose your privacy level — Umbra handles the rest.
What Makes Umbra Different
Privacy defaults that work — without a PhD in browser configuration
Privacy Control Center
Three presets — Balanced, Strict, and Maximum — instead of tweaking 200+ about:config flags. Per-site overrides let you relax settings for banking or work without touching global preferences.
WASM Sandbox
WebAssembly execution is sandboxed via WASI SDK. Untrusted WASM code is isolated by default, adding a meaningful layer of security hardening over stock Firefox.
Transparency Page
about:umbra lists every setting changed from stock Firefox ESR — no hidden modifications, no mystery. You always know exactly what Umbra has done to protect your privacy.
DRM Opt-In
Widevine is disabled by default for maximum privacy, but you can enable it with one click. Netflix, Disney+, and other streaming services work fully when you opt in.
uBlock Origin Built-In
uBlock Origin comes pre-installed and pre-configured. You get 100% ad and tracker blocking the moment you launch Umbra — no setup, no popups asking you to install extensions.
Zero Telemetry
All Firefox telemetry, crash reporting, studies, and data collection are disabled at build time using enterprise policies. Umbra never phones home to Mozilla or anyone else.
Why Choose Umbra?
Compared to the alternatives
Vanilla Firefox
Telemetry enabled by default. Sponsored content in the new tab page. Weak privacy defaults. Requires significant manual configuration to become private.
Umbra ✓
Strong privacy defaults out of the box. Works with streaming, banking, and everyday sites. One-click privacy presets. Fully transparent about what's changed.
Librewolf
Maximum privacy but breaks many sites. No DRM or streaming support. Config-only adjustments. Challenging for everyday use without technical knowledge.
Download Umbra
Free for Windows and Linux. No account required.