Cookie inspector & Set-Cookie builder

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Paste a Cookie request header or Set-Cookie response header to inspect it — or build a new Set-Cookie line with the usual attributes.

Mode

Everything runs in the browser — cookie values never leave this page.

About this tool

Browsers store small name=value pairs called cookies. The server sends them with Set-Cookie on a response; the browser echoes them back in a Cookie header on later requests.

Attributes like Path, Domain, Max-Age, Secure, and SameSite control where the cookie is sent and how long it lives. Getting them wrong is a common source of “login works locally but not in prod” bugs.

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