📨 PostMessage Handler Tester

Test cross-origin postMessage flows like Perfetto's embed API

This Page's Headers

COOP

COEP

CORP

DIP

Target Setup

This Page's Origin

Target Origin (cross-origin)

Leave empty for same-origin testing

Open Target As Target Path Target Headers

COOP

COEP

CORP

DIP

PING/PONG Test

Send PING, expect PONG reply

Ready...

Send Trace Buffer

Trace Format Title (for wrapped)

Ready...

Send ScrollToRange

Time Start (seconds) Time End (seconds)

Ready...

Message Log

Listening for messages...