nth Labs
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nth Labs is the testing team for people who build with AI.

Agents use your app like real customers.
Reports for IT, Marketing and Finance show what to fix.

Try it on our sample app

Free, no account needed. Results in about a minute.

The console’s home for Acme Notes, our sample app: “11 findings affect customers.” First on the list: “‘Subscribe’ on Page not found did nothing when submitted”.

No setup, no tests to write

Paste a link. Agents open every page and map your app before testing it.

See how a first run works
Brain, the map the run built of Acme Notes: its 9 screens, its audience and its 31 open findings, drawn as one graph.

Catch bugs before your users do

Agents click every button and fill every form in a real browser, and show you what failed.

See what IT checks
The IT page for Acme Notes: “10 things to fix first on 5 pages, all of them break for customers.” The fixes are listed in order, the first one open beside them.

See how your pitch lands

Find the claims your pages can’t back up, and hear how simulated buyers from your market react.

See what Marketing checks
Settings, Testers: a panel drawn from population data to match the audience, filtered by device, region, tech comfort and attitude, with the people the draw seated.

Know what your app could earn

See what stops people paying, what each fix is worth and what your first year could make.

See what Finance checks
The Lab on Acme Notes, sized on its own funnel and drawn as the band the runs land in rather than one number. By month 12: $7,408, and half the runs land between $4,204 and $12,937.

Where it runs

Use nth Labs from the console, on every deploy, or inside your coding agent.

Console

Each finding comes with its proof and a fix you can paste into your AI tool.

Tour the console

CI

Add one webhook and every deploy gets checked. Pull requests get a pass or fail.

Running in CI

Coding agents

Claude, Codex and Cursor fix your findings, and nth Labs confirms each fix in a real browser.

Connect your agent

Published results

Each one comes with its method and what it missed.

400 of 400

planted bugs caught, across 21 kinds

We break test apps on purpose and count what nth Labs finds. The last run missed none.

See the method

193

real products, read like a first-time visitor

Almost a quarter offer no way to reach a person.

See the findings

Try nth Labs now.

Paste a link to run your first check. No account needed.

Checks that don’t use AI are free on every plan. No card needed. See pricing