01 / TIMING
See where the time goes.
Follow requests across a timeline. Spot slow responses, overlaps, and retries.
THE WEB, UNDER THE HOOD
See it.
Shape it. Send it.
A web debugging proxy that puts your app’s traffic in your hands. Inspect requests, find the surprises, and try a different response.
Download Windows previewFree & open source Windows x64 & ARM64
HTTP / HTTPSWebSocketsServer-sent eventsJSON & binary bodiesSaved traces
FOLLOW THE CLUES
From “that’s odd”
to “there it is.”
Keep the request, the response, and the bigger picture together.
02 / REPLAY
Change it. Try it again.
Take a captured request into Composer, change the details, and inspect the result.
Make the next response your own. Pause exchanges with breakpoints, rewrite headers, or serve a saved response.
YOURS TO EXPLORE
Open the hood.
Free to use. Open to change. MIT licensed.