Why this tool is useful
Use Cookie Header Parser when you need to split a pasted Cookie request header into decoded names, values and duplicate warnings. The result is immediate and easy to verify before you reuse it.

split a pasted Cookie request header into decoded names, values and duplicate warnings.
Ready. Your working data stays in this browser.
Use Cookie Header Parser when you need to split a pasted Cookie request header into decoded names, values and duplicate warnings. The result is immediate and easy to verify before you reuse it.
Enter the values requested by Cookie Header Parser. The browser validates the input, performs the calculation locally and produces a copyable result with clear errors.
A practical use is to run Cookie Header Parser on a small sample first, confirm the output, and then process the complete value or list.
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.