WebSocket messages

The Network tool reads WebSocket traffic as messages, not bytes. Open a WebSocket request and the Messages tab lists what went each way, with the time since the connection opened.

• Arrows show the direction: up goes from the app to the server, down comes back.
• Text messages show as text, and JSON is pretty-printed when you open one. Binary messages show a hex dump.
• The filter looks inside text messages.
• Control frames (ping, pong, close) are listed too.

How it is read#

The proxy still copies every byte between the app and the server unchanged and only listens in. It follows RFC 6455: frames with 7, 16 and 64 bit lengths, masks, fragmented messages joined back into one, control frames in between them, and permessage-deflate when the two sides agreed on it (including no_context_takeover). If what flows is not WebSocket after all, the reading stops quietly and the connection carries on.

Limits#

A flow keeps up to 1,000 messages and 64 KB of each; the tab says how many later messages were not kept, and when a message was cut. The counts keep going. The HAR export includes the messages in _webSocketMessages, as Chrome does.