Cookie converter: Netscape and JSON
Convert cookies between the Netscape cookies.txt format, the JSON array that cookie-editor extensions export, a { cookies: [...] } object, a Playwright storageState, and a Cookie: header line. The input format is detected for you, and every field is carried across. It runs entirely in your browser — nothing you paste is uploaded or stored.
Cookie: header carries no domain, so give one to convert it to the other formats.
Cookies are credentials. That is why this runs on your machine and sends nothing. A row that cannot be read is listed by its line number rather than dropped — a cookie silently skipped is a login that silently does not work.
What each shape holds
All of them store the same thing — name, value, domain, path, and the flags that decide when a browser sends the cookie — but they spell it differently. The converter reads the fields out of one and writes them into another without losing secure, httpOnly, sameSite or the expiry.
Netscape cookies.txt
Seven tab-separated fields per line, used by curl and wget. A #HttpOnly_ prefix on the domain marks an HttpOnly cookie; expiry 0 means a session cookie.
JSON array
What cookie-editor and EditThisCookie export: one object per cookie with name, value, domain, expirationDate and the flags.
storageState / object
Playwright’s storageState and the { cookies: [...] } shape many tools import, including Mosaic.
Cookie header
The name=value; name=value line a browser sends. It has no domain or flags, so converting from it needs a domain you supply.
- Paste your cookies. Paste a Netscape cookies.txt file, a JSON array from a cookie-editor extension, a { cookies: [...] } object, or a Cookie: header line.
- Pick the output. Choose the format you want out. The input format is detected for you, and every field — secure, httpOnly, sameSite, expiry — is carried across.
- Copy the result. Copy the converted cookies. Rows that cannot be read are listed by line number rather than dropped silently.
Does this cookie converter upload my cookies?
No. The conversion runs entirely in your browser; nothing you paste leaves the page or is stored. Cookies are credentials, so this matters — keep them to yourself.
Which formats does it read and write?
Netscape cookies.txt (the tab-separated format, with #HttpOnly_ honoured), a JSON array from cookie-editor extensions, a { cookies: [...] } object, a Playwright storageState, and a Cookie: header line. It converts between them and keeps secure, httpOnly, sameSite and expiry.
What happens to a malformed row?
It is listed by line number rather than dropped. A cookie silently skipped is a login that silently does not work, so the tool names what it could not read, the same rule Mosaic uses when it imports a jar.
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