Independent engine
Firefox runs Gecko, the only major engine that is not Chromium or WebKit. If keeping the web pluralistic matters to you, that alone is a reason to use it.
The Firefox alternative your AI can actually drive.
Firefox is the great independent-engine, privacy-minded browser. Sessionat is the open-source browser your AI controls through MCP, with Arc-style workspaces and auto-saved sessions on top of Chromium.
At a glance
Sessionat
Firefox
Engine
Chromium
Gecko (independent)
AI control (MCP)
Built in: Claude, Cursor
Opt-in sidebar AI chat
Auto-saved sessions
Every 30s, named restore
Manual restore on crash
Workspaces
Arc-style sidebar
Multi-Account Containers
Open source
Yes (MIT)
Yes (MPL)
Price
Free
Free
Compiled June 2026 from public sources. Browser features change fast, so verify before relying on a detail.
The trade-off
Firefox protects the open web. Sessionat hands the web to your AI.
Firefox is the most important non-Chromium browser there is. Its Gecko engine keeps the web from becoming a one-engine monoculture, its privacy work (Enhanced Tracking Protection, resist-fingerprinting) is genuinely strong, and it runs everywhere, including Windows, Linux, Android, and iOS.
What Firefox does not do is let an AI assistant drive it. Its sidebar AI is an opt-in chat panel, not an agent that can click, type, and navigate for you. Sessionat is built around that: connect Claude, Cursor, or any MCP client and it works the web in your real browser, on the accounts you are already signed into, with auto-saved sessions so you never lose your place.
The honest catch: Sessionat is Chromium, not an independent engine, and it is Mac-first today (Linux and Windows are on the roadmap). If engine diversity or running on Linux today matters most, Firefox is the better pick.
| Feature | Sessionat | Firefox |
|---|---|---|
| Built-in AI control via MCP | ✗ | |
| AI acts on your real logins | ✗ | |
| Arc-style workspaces | Containers | |
| Auto-saved session journal | ✗ | |
| Local visit analytics your AI can search | ✗ | |
| Open source | ||
| Independent (non-Chromium) engine | ✗ | |
| Windows, Linux, and mobile today | Mac now | |
| Resist-fingerprinting privacy mode | Local-first |
Honest assessment
Where Firefox is the better choice.
Everywhere, today
Firefox runs on Windows, macOS, Linux, Android, and iOS right now. Sessionat is Mac-first, with Linux and Windows on the roadmap.
Anti-fingerprinting
Firefox and its forks lead on resist-fingerprinting (looking like everyone else). Sessionat focuses on local-first data, not fingerprint uniformity.
A decade of add-ons
Firefox has a mature add-on library on AMO and years of stability behind it.
FAQ
Real questions about switching from Firefox.
Is Sessionat based on Firefox?
No. Sessionat is built on Chromium, the same engine as Chrome, Edge, Brave, and Arc. Firefox uses its own Gecko engine.
Can Firefox be controlled by AI the way Sessionat can?
Firefox has an opt-in sidebar AI chat, but not agentic control of the browser. Sessionat exposes the open MCP standard so Claude Desktop, Cursor, or your own scripts can click, type, navigate, and read pages for you.
Will my Firefox add-ons work in Sessionat?
Not directly. Firefox add-ons come from AMO and target Gecko; Sessionat is Chromium, so it installs Chrome Web Store extensions instead. Most popular tools (uBlock Origin, 1Password, and so on) have a Chrome version.
Does Sessionat run on Windows or Linux like Firefox?
macOS today, on every Mac from 2018 onward. Linux is targeted for mid-2026 and Windows for late 2026.
Is Sessionat private like Firefox?
Sessionat is local-first with no telemetry: sessions and visit history stay on your Mac. Firefox leans on resist-fingerprinting and tracking protection. Different emphases, both privacy-respecting.
Give your AI a real browser.
Free, open source, no account needed. Keep Firefox installed and try Sessionat side by side.
Download Sessionat for Mac (free)