How Instant Replay works

When you capture a bug, BugMojo attaches an Instant Replay so anyone on your team can watch exactly what happened. It looks like a video, but it works in a smarter way. Here is what it really is and why that matters.

A screen recorder saves a stream of pixels. Instant Replay does something different: with the open-source rrweb engine it records the DOM (the live structure of the page) plus every change to it as you click, type, and scroll. On playback, BugMojo replays those changes to reconstruct the page in the browser. You are watching a rebuilt page, not a movie of your screen.

Recording structure instead of pixels has three big payoffs:

• Tiny. A stream of DOM changes is far smaller than a video, so replays upload fast and cost little to store.
• Sharp. The page is redrawn by the browser, so it stays crisp at any window size or zoom, with no blurry, compressed frames.
• Inspectable. Because it is real page structure, developers can pause the replay and dig into elements and layout, not just squint at pixels.

The replay does not travel alone. BugMojo lines up the console logs and network requests that happened during the session against the same timeline. Scrub to the moment the bug appears and you can see the error that fired and the request that failed at that exact instant, turning "it just broke" into a clear cause.

Instant Replay keeps a rolling window of the last 30 seconds before you capture by default. You can switch it to 15 seconds, 1 minute, or 2 minutes in the extension settings. That is long enough to show the steps that led to the bug, but short enough to stay lightweight and focused. Reviewers see the reproduction, not hours of unrelated browsing.