How it works

From URL to bug report.
Automatically.

Give Replay QA a URL. It explores your app, records every session with our time-travel debugger, and delivers a root cause and suggested fix for every bug it finds.

How it works

From URL to bug report — automatically

What you get

Root cause. Suggested fix. Full recording.

Every bug Replay QA finds comes with everything your agent needs to fix it — not just “something broke.”

Bug found

confidence: high

Checkout button does nothing on mobile Safari

Root cause

handleSubmit is never called because the button is rendered outside the <form> element after the responsive layout change on screens under 768px.

Suggested fix

Move the button inside the form, or add form="checkout-form" to the button element.

Evidence

Replay recordingDOM mutationsNetwork traceReact state

Example output — actual reports are generated from your app's real runtime data.

Ask Your Agent

One prompt. Your agent does the rest.

Try feeding this prompt to your coding agent to see the magic unfold.

Use Replay QA to test this app. Create a QA project for my running app, wait for the results, fix any open bugs, and keep looping until the app passes.

View full agent prompt

Set up a continuous QA loop for the app we're building using Replay QA (https://loop-qa.replay.io).

Drive everything through the REST API at https://loop-qa.replay.io/api/v1 — read the OpenAPI spec at /api/v1/openapi.json first; it documents the full workflow. Authenticate with my API token ("Authorization: Bearer lqa_..."), asking me for it if needed.

Your job:
1. Create a QA project for the running app — give it the target_url and a short note on the key flows. If the app is only reachable from this machine (e.g. http://localhost:3000), enable the reverse proxy and follow the spec's setup steps.
2. Let QA run — poll the project status and don't kick off explorations or test runs yourself; QA drives those.
3. For each open bug, read its full root-caused report and apply the fix directly in the codebase, then mark it fixed via the API.
4. Keep looping until no open bugs remain.

Works with Codex, Claude Code, Cursor, and any agent you're using.

The technology

Underneath it all: our time-travel debugger.

Whether you're running Replay QA on a web app or analyzing a CI failure, the same recording engine is at work. Replay captures the full browser runtime deterministically — making AI analysis possible where it wasn't before.

Render chainsWhich component re-rendered, what triggered it, what changed

State flowRedux actions, React state updates, context changes across the component tree

Network timingEvery request and response, with exact payload and timing data

JS executionEvery function call on every frame, with arguments and return values

DOM mutationsWhat changed in the DOM, when, and what code caused it

This isn't guessing from error messages. It's reading the actual execution.

Test your app for free.

Give Replay QA a URL. No test suite, no QA team, no credit card required.

From URL to bug report.Automatically.