Your browser should be as personal as your WM config.
Umbra is a browser built on Tauri that treats customization as the default, not a settings page. Every piece of chrome mounts into slots you can tear out and rebuild, one TOML file drives it all, themes and plugins come from the community, and nothing ever phones home.
Built for people who configure everything
Tear It Down, Rebuild It
Tab bar, URL bar, bookmarks bar, sidebar, status bar: every component mounts into named slots. Remove one and it's never instantiated; remount it wherever you want. Nothing about the chrome is sacred.
One TOML to Rule Them All
Layout, theme, keybindings, flags: all in one file at ~/.config/umbra/umbra.toml. Save it and changes apply live, no restart. Malformed edit? Umbra rolls back to the last-known-good snapshot automatically.
Themes From Tokens to Total Rebuilds
A token file swap reskins everything; full component replacement goes all the way to boxy TUI-style. Glassmorphism by default. Grab packages from the community gallery or a GitHub URL, preview the diff before anything applies.
Sandboxed Plugins
Lua and WASM plugins gated by capability manifests: no filesystem, no network, unless you explicitly grant it. Per-plugin memory and CPU caps keep a runaway plugin from pegging your machine.
Bring Your Browser With You
On first launch (or any time after) import bookmarks and history from installed Chromium- and Firefox-family browsers, detected automatically. Config and bookmarks sync to a private GitHub gist you control; history never syncs. Passwords are never imported.
Scriptable From Outside
A Unix control socket at ~/.config/umbra/umbra.sock takes one command per line: list tabs, open a URL, switch layout, reload config, quit. Wire it into your bar, your scripts, or your window manager bindings.
Private by Default
The ad and tracker blocker ships enabled (and removable, like everything else). No telemetry, no cloud calls anywhere in the browser. Privacy here is architecture, not a checkbox.
Local AI, When You Want It
Page summaries, reading-assistant Q&A, and natural-language tab search through your own Ollama instance. Off by default, bound to 127.0.0.1, and zero data leaves your machine when it's on.
Six Layout Engines
Compact, Sidebar, Minimal, Tiling, Floating, or Zen — switch any time from the command palette or
Ctrl+Alt+L. Tiling splits the view side by side; Zen fades the chrome away entirely.
Free and open source
Grab the build for your platform — or clone it and build it yourself.
Prefer to build it yourself? Clone the source. See the Downloads page.