Sendwire

The developer's HTTP client. It sends the request and shows you the DNS lookup, the TCP connect, the TLS handshake, the certificate chain and every byte in both directions.

These pages describe what it does and how. If you are looking for the shortest possible start, send your first request; if you are here because a request is behaving oddly, reading the wire is the page that matters.

What is here

Install	macOS, Windows, Linux. No account.
Your first request	Sixty seconds, end to end.
Reading the wire	The tab everything else is built around.
Scripting · script reference	Real JavaScript, not a template language.
Suites · Load testing	Chain requests, then put them under load.
Command line	The same runs, in CI.

Where your data lives

In a JSON file on your disk, at a path the app will tell you — bottom left of the window, and sendwire where on the command line. It is saved as you type.

There is no account, no sync and no cloud. Nothing is sent anywhere except the requests you ask for.