AliasMode Firefox engine
The antidetect browser you can fully audit.
AliasMode Firefox is our own custom antidetect Firefox. Fingerprint protection runs inside the C++ engine, every patch is public, and in Local mode your profiles never leave your computer. Prefer Chromium? AliasMode Chromium is our own Chromium 155 engine.
Direct answer
AliasMode Firefox is the open-source antidetect browser engine built and maintained by AliasMode. It spoofs fingerprints inside Firefox’s C++ code, not with injected JavaScript. The engine, its patches, and its build pipeline are public under MPL-2.0, and the AliasMode app that manages it is Apache-2.0. Each profile can use AliasMode Firefox or Chromium through CloakBrowser.
Our own engine, not a closed binary
Most antidetect browsers ship a closed engine. You cannot check what it spoofs, what it leaks, or what it sends home. You have to trust the vendor.
AliasMode Firefox is different. We build the engine ourselves, publish every fingerprint patch, and ship it inside AliasMode as a verified download. You can read the code and build the engine yourself.
Fingerprint protection inside the engine
Spoofing happens in Firefox’s C++ code before a page can run a script. Pages cannot hook it, and they cannot find a patched JavaScript API. Each profile gets its own consistent Firefox identity, saved once and reused on every launch.
- Navigator and screen: user agent, platform, hardware concurrency, touch points, and window geometry
- Graphics: WebGL vendor, renderer, parameters, and extensions
- Audio: AudioContext output and sample rate
- Fonts: system font list, CSS system fonts, and font metrics
- Network: WebRTC IP, locale, timezone, and geolocation matched to the profile proxy
- Media: media devices, codecs, and speech voices
- Automation: a hidden Playwright agent that page scripts cannot see
Open source from engine to app
| Component | License | Source |
|---|---|---|
| AliasMode desktop app, Local API, and MCP server | Apache-2.0 | github.com/aliasmode/aliasmode |
| AliasMode Firefox engine | MPL-2.0 | github.com/aliasmode/aliasmode-firefox |
| AliasMode Chromium engine (Chromium 155) | GPL-3.0 | github.com/aliasmode/aliasmode-chromium |
| CloakBrowser engine for Chrome 146 (optional, Windows) | Third-party license | Included at no extra cost |
| AliasMode Cloud sync (optional) | Hosted service | Not required for Local mode |
AliasMode Firefox is our engine, built on top of Camoufox. We maintain it, harden it, and release it with AliasMode.
Local and private by default
In Local mode, AliasMode needs no account and sends nothing to AliasMode Cloud. Profiles, cookies, and fingerprints stay on your computer. Firefox telemetry and data reporting are removed from the engine when it is compiled.
- No AliasMode account in Local mode
- No profile data sent to AliasMode Cloud in Local mode
- Engine telemetry removed at compile time
- Every engine download is checked against a pinned SHA-256 hash
- Optional Cloud sync for teams, with encrypted portable profiles
Firefox or Chromium: pick per profile
Each AliasMode profile uses one engine. Choose AliasMode Firefox for a fully open engine. Choose Chromium through CloakBrowser when a workflow needs Chrome extensions or Playwright over CDP.
| AliasMode Firefox | Chromium (CloakBrowser) | |
|---|---|---|
| Engine source | Open source (MPL-2.0) | Third-party engine |
| Fingerprint spoofing | C++ inside Firefox | Patched Chromium source |
| Automation | AliasMode Scripts (Playwright) | Scripts, Local API, Playwright over CDP, MCP |
| Chrome extensions | Not available | Supported |
| Platforms | Windows x64, macOS (Apple Silicon and Intel), Linux x64 | Windows installer, macOS app |
| Cost | Free | Free, included at no extra cost |
Start with AliasMode Firefox
Install AliasMode
Download AliasMode 0.1.0-beta.50 or newer, then sign in to Cloud or continue locally.
Create a profile
Select AliasMode Firefox as the engine and add a proxy if the account needs one.
Open the profile
AliasMode downloads the engine, checks its hash, and opens the profile with its saved identity.
Frequently asked questions
Is AliasMode a CloakBrowser wrapper?
No. AliasMode ships two open-source antidetect engines of its own: AliasMode Firefox and AliasMode Chromium. CloakBrowser is an optional engine for Chrome 146 profiles on Windows. AliasMode also adds profile management, per-profile proxies, Scripts, Cloud sync, the Local API, and MCP servers for AI agents.
Is AliasMode Firefox open source?
Yes. The engine, its fingerprint patches, and its build pipeline are public under MPL-2.0 at github.com/aliasmode/aliasmode-firefox. The AliasMode app is Apache-2.0.
Does my data stay on my computer?
In Local mode, yes. AliasMode needs no account and sends no profile data to AliasMode Cloud. Cloud mode is optional and syncs encrypted portable profiles for teams.
How is AliasMode different from Donut Browser?
Donut Browser’s app is open source, but its Wayfern antidetect engine is closed source, and its MCP and automation APIs need a paid plan. AliasMode’s engine and app are both open source, and every feature is free.
Does AliasMode Firefox cost anything?
No. AliasMode Firefox, AliasMode Chromium, Local mode, and Cloud sync are all free with unlimited profiles.
Can I still use Chromium?
Yes. New Chrome profiles use AliasMode Chromium, our own Chromium 155 engine. On Windows you can also select Chrome 146 through CloakBrowser. Choose the engine when you create a profile.