Cookie converter
Convert cookies between the three formats developers actually deal with — the Netscape cookies.txt file, the JSON array that browser extensions and tools like Puppeteer use, and a raw Cookie: header string. Everything is converted locally; nothing is sent anywhere.
The three formats
JSON array — objects with name, value, domain, path, expires, secure, httpOnly. This is what browser cookie-editor extensions export and what automation frameworks import. Netscape cookies.txt — the tab-separated format used by cURL and wget (domain flag path secure expiry name value). Cookie header — the name=value; name2=value2 string a browser puts in the Cookie: request header. Conversion is lossy in one direction only: a header string carries just names and values, so domain and expiry are left blank when converting from it.
Cookies are session secrets. This tool runs entirely in your browser and transmits nothing — but never paste cookies into a site you do not trust.