Version 1.4.1 · 97 tools · your pages stay on your machine
Your AI, already signed in.
Inspect and copy CSS from any element. Capture full-page screenshots that handle sticky headers and lazy loading. Read Markdown as a document. Then hand the wheel to Claude Code/Desktop, Cursor, VS Code, Windsurf, Antigravity, IntelliJ, Codex, Grok Build, Kimi Code/Desktop, JCode, Cline, OpenCode, Continue.dev, KiloCode, Roo Code, Aider, OpenClaw, Hermes, OpenFang or any other MCP client — driving the browser you are already signed into: your real profile, your real sessions, no logins to hand over.
Chrome, Brave, Edge, Opera and Chromium use the same store package. Firefox is partly supported — see what differs.
Browser control for your AI needs no account. Sign in free for three uses a month of the free extension tools. Pro is $29.99 once, up to five signed-in browsers, no subscription, and unlocks the Pro tools.
Watch the walkthrough
88 seconds: snapshot to action, signed-in sessions, network capture, CSS to components, record and time-travel, audits.
Why this exists
The automation layer is not the moat
Chrome DevTools MCP, Playwright MCP, mcp-chrome and Browser Use are free, well funded and good. We are not going to out-free Google and Microsoft, and we do not pretend to.
The moat is the browser you already use
Other tools start a fresh, logged-out browser and ask you to hand over credentials or API keys. T3rnel works in the one you are signed into right now, so your AI can do what you can do: open the dashboard you are in, read the page behind the login, fill the form, capture the result. Credentials are redacted before they reach the model, and if you want to be asked before a page changes, the approval gate is one switch away. It ships off.
Your real browser, your real sessions
No separate automation browser, no re-authenticating, no automation flags. The agent works in the profile you are already logged into — which is the honest version of the capability other tools chase with fingerprint spoofing.
What you get
CSS inspection
Hover any element and get its real, clean, copyable CSS — with the units the author actually wrote.
Full-page screenshots
One click, the whole page, stitched — and it handles the real web rather than the ideal one.
Markdown viewer
Read .md files as documents, including the ones your agent just wrote.
Page audit and link checking
Accessibility, spelling and links — reported honestly, including what could not be checked.
Record, replay and code export
Click through a flow once. Get a maintainable test that runs in your CI without this extension.
Agent safety
The part that justifies the price: a valve between a language model and your logged-in browser.
Encrypted identity vault
Per-site credentials, encrypted on your device, never written in the clear.
Color picker
Sample and compare colors from any pixel on the page, with palette export.
Clear cache and hard reload
Clear the cache for the current origin and hard-reload the page without digging through DevTools.
React debugging
Inspect the React component tree, props and hooks on pages that use React.
Form filling and clearing
Fill forms from MCP instructions or the side panel, and empty them again, with field detection and structured values.