How to use the cookie string parser
A cookie line copied from the network tab of your developer tools is one long run of semicolons, which is painful to read by eye. This tool splits that line into names and values and lays them out in a table, which helps when you are chasing a session that keeps logging out or checking which cookies are actually being sent.
There are two kinds of cookie strings. The Cookie header a browser sends up contains nothing but cookies. The Set-Cookie header a server sends down holds one cookie followed by its attributes: Path, Domain, Max-Age, Secure, HttpOnly, SameSite and friends. Automatic detection looks for those attribute names and reports which reading it used. If the guess is wrong, pick the mode yourself and split again.
Cookie values are frequently percent-encoded, showing up as runs like %E2%9C%93. With the decode option on, the readable original is shown instead; a value whose encoding is malformed is left exactly as it was, and the result tells you how many failed. Value length is counted in code points.
Cookies often hold a session token that grants direct access to an account. Input and output stay inside your own browser and nothing is uploaded, but it is still worth avoiding pasting a real cookie into a public post or a chat room.
Frequently asked questions
If attribute names such as Path or Secure appear, it reads the string as Set-Cookie. When the guess is wrong you can choose the mode yourself and split again.
That is percent encoding. Turn on the decode option to see the original characters; malformed values that cannot be decoded are kept as they are.
No. Splitting happens purely in JavaScript inside your browser. Session tokens are sensitive all the same, so keep them off public pages.