This tool runs entirely in your browser. Nothing is sent to the server.

Paste message headers

Raw headers

Parsed locally. Nothing leaves your browser.

How this works

Privacy: Message headers contain recipient addresses, internal hostnames and subject lines. Passing them as a query parameter would record all of it in the shareable URL, your browser history and the server access log. This tool therefore accepts no header parameter and parses locally in JavaScript.
What it shows: The Received chain in chronological order with the delay at each hop, the originating IP, and any SPF, DKIM and DMARC results the receiving server recorded.