An AI that actually uses the page you’re on.
Katharina sits in your browser’s side panel and works on whatever is open — reading it, filling it, scanning it, watching it. It asks before anything sends, and it never touches a payment field.
Do it once. Then do it forever, for free.
- 01
Ask once
You describe the task. Katharina works it out on the real page, step by step.
- 02
It compiles
The finished task becomes a parameterised recipe — with its own notes on what it does.
- 03
Replay free
Every rerun is mechanical. Change the city, change the count, run it tomorrow. No credits.
Four things it does on any site
Understand any page
Summarise an article, pull out the details you need, or scan a long list of results — without copying anything into a chat box.
Fill forms fast
Save your details once, then let Katharina complete applications and sign-ups, including awkward dropdowns and multi-page flows.
Reply in place
It reads a conversation and drafts a reply in the page’s own message box, in any language. You press send.
Watch and react
Ask it to keep an eye on a page and tell you when something new arrives. It works by watching the page change — no site-specific setup.
Runs don’t die. They wait for you.
- A captcha appearsThe run pauses. You solve it. One click continues from the same item.
- You close the panelProgress is on disk. Reopening offers to continue — or to download what it got.
- The browser restartsA notification when Chrome comes back, and the same one-click continue.
- You press PauseIt finishes the step it is on first, so the page is never left half-done.
You stay in control
- Read the pageHappens automatically.
- Fill a fieldAutomatic, and you see every value.
- Send or submitStops and asks you first. Every time.
- Payments, passwordsRefused outright, in the code.
The five people ask first
- Which sites does it work on?
- Any of them. Katharina reads the page structure rather than using per-site integrations, so a job you build on one site works the same way on another. Some sites restrict automated interaction in their terms — that is your call to make, and the panel keeps you in the loop on every consequential action.
- What leaves my browser?
- With your own API key: nothing goes to us at all — the request goes from your browser straight to the model provider. With Katharina credits: the page content in your request passes through our server to reach the provider, and we never store it. Not the prompts, not the replies. Only token counts, so we can bill you.
- What happens at a captcha?
- It stops and asks you to solve it, then carries on from exactly where it was. Katharina never solves, bypasses or retries through a security check — the whole point is that a human is right there. Runs don’t die at a wall; they wait for you.
- Can I stop it?
- Always. Every surface showing work in progress carries Pause and Stop in the same place. Pausing finishes the current step first, so the page is never left half-done, and continuing later costs nothing.
- Do I need an account?
- No. With your own API key from Anthropic, Google or Groq, Katharina runs entirely in your browser and there is nothing to sign up for. An account is for using Katharina credits instead of your own key.
It works on the page you have open right now.
Free to install. Bring your own API key, or use Katharina credits.