Session Replay for Debugging: Reproduce Any Bug From a Recording

Most bugs don't die because they're hard to fix. They die in a back-and-forth: 'Can't reproduce — what were the exact steps?' The reporter doesn't remember, the environment is different, and the ticket goes stale.

Session replay removes that loop. It records the DOM, console, and network of a real session and lets you replay it pixel-for-pixel — so reproduction stops being detective work and starts being a button you press.

It's not a video. Tools like rrweb serialize the DOM and then record incremental mutations — clicks, inputs, scrolls, route changes — as a compact JSON event stream. On playback, the recorder rebuilds the page and re-applies each event in order. Because it's the real DOM, you can open dev tools inside the replay and inspect any element at any moment.

• DOM mutations — every element change, in order, with timestamps.
• Console — logs, warnings, and the exact error with its stack trace.
• Network — requests, status codes, and payload shapes.
• User input — clicks, keypresses (masked), scroll, and viewport size.

The expensive part of debugging is usually getting the bug to happen again. A replay collapses that to a single click, and it carries the three context streams you'd otherwise reconstruct by hand — what the user saw, what the code logged, and what the network returned.

1. Capture — the browser extension or SDK records the session quietly in the background.
2. Attach — when a user clicks 'report a bug', the last N seconds of replay, console, and network are attached automatically.
3. Reproduce — open the replay, scrub to the error marker, and watch the exact interaction that broke.
4. Hand off — share a link, or let an AI agent read the structured context over MCP and draft the fix.

Also budget for size — record incrementally and cap the buffer to the last minute or two — and test your replays across the browsers your users actually use, not just the one on your desk.