Is that unsubscribe really one-click?
Paste an email’s raw headers and this page tells you which exit the sender actually gave you: a true RFC 8058 one-click, a link to a page, a mailto:, or nothing at all.
Everything runs in your browser. Your paste is never uploaded — check the network tab. The parser is a static JavaScript file; no request this page makes ever carries your text, and nothing you paste is stored or logged. The page does load the site’s standard page-view analytics — they count the visit, never see the paste.
Paste your raw headers above, then press Analyze. Nothing leaves this page.
The four answers
List-Unsubscribe-Post plus an https target. One machine request and you are out. Machine clicks: 1.List-Unsubscribe header. This sender gives robots nothing — the footer link is all you have.Find your headers
Gmail
Open the message, click the ⋮ menu at the top right of the email, then Show original. Copy everything from the new tab — the headers are the block at the top, above the first blank line.
Apple Mail (macOS)
Select the message, then View → Message → All Headers (or press ⇧⌘H). Copy the header block that appears above the message body.
Outlook (desktop)
Open the message in its own window, then File → Properties. The header block sits in the Internet headers box at the bottom — select it all and copy.
Don’t trim anything — pasting the whole “Show original” page (Gmail: ⋮ → Show original → select all) is fine. The checker finds the header block on its own and never reads past it into the body.
Questions
What is a one-click unsubscribe?
RFC 8058 one-click needs two things in the email: a List-Unsubscribe header with an https target, and a List-Unsubscribe-Post: List-Unsubscribe=One-Click header. Together they let your mail client unsubscribe you with a single machine request — no web page, no login. Since February 2024 Gmail and Yahoo require it of bulk senders (5,000+ messages a day).
Why is a mailto: unsubscribe weaker than an https one?
A mailto: exit means your mail app sends an email to the sender and someone — or something — on their side is supposed to act on it. There is no machine click path, no standard response, and no way to tell whether it worked. An https target with the one-click header is a request that either succeeds or fails, visibly.
Does this tool upload my email anywhere?
No. The parser runs entirely in your browser as a static JavaScript module, and the page makes no network calls with your text. Nothing is sent, stored or logged — open your browser’s network tab and press Analyze to confirm it yourself.
An https link is present, so why does it say "not one-click"?
Because a link is a page, not a promise. Without the List-Unsubscribe-Post header nothing can unsubscribe you automatically; the link opens a page, and that page can ask for a login, fifteen toggles, or a confirmation you never finish. The gap between those two exits is exactly what the Exit Gap Index measures.
Where this comes from
This checker runs the same parser the Exit Gap Index uses to read the machine path — the exit Google forces bulk senders to give robots. The Index measures what happens next: the human path, the maze a person actually walks. One click for a machine, four for you, is a gap worth grading.
Want to feel that maze rather than read about it? Play the Unsubscribe Museum.
Found a sender whose exit deserves a grade? Tell us: hey@flicked.email.
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