General
Changes apply immediately and are saved for next time.
Appearance
Light, dark, or follow your system theme.
Default search engine
Used when you type a search into the address bar.
Search engines
Tick which appear in the toolbar's search dropdown. Add your own with a URL containing
%s — e.g. https://searx.be/search?q=%s. Theseus also offers to add a site's own search when you visit one.Reopen tabs on launch
Restore the tabs from your last session when Theseus starts.
Performance
Keep Theseus light on resources.
Throttle inactive tabs
Background and inactive tabs use far less CPU. Recommended.
Privacy
Reduce tracking and lock down device access.
WebRTC IP policy
Controls which IP addresses WebRTC may reveal — the same thing the "WebRTC Network Limiter" extension does, built in. Public interface only hides your local IP; Disable non-proxied UDP is strongest. Tor forces the strongest automatically.
Block camera
Deny camera by default — also hides its name from fingerprinting.
Block microphone
Deny microphone by default — also hides its name from fingerprinting.
Hide media devices
Blank the labels and IDs of all cameras, microphones and speakers from
enumerateDevices() — closes a WebRTC fingerprinting leak, like Firefox.Anti-fingerprinting
For each: Show (real), Hide (neutral value), Spoof (a decoy), or Manual (set your own).
Timezone
What sites read via JavaScript (Intl / Date).
Language
navigator.language and the Accept-Language header. Spoof reports a major world language; Manual lets you type any locale.
Location
Hide denies geolocation; Spoof reports a chosen region; Manual reports exact coordinates.
These reduce tracking and hide your IP, but a custom browser can still be fingerprinted. For maximum anonymity, use the Tor Browser.