What this tool does
The HTTP Header Parser processes headers line by line, separating names and values only by the first colon of each line. Headers with the same name will be retained as arrays to prevent repeated fields such as Set-Cookie from being overwritten by the latter value; the tool will not request the header from any website.
- Supports plain text of request headers and response headers.
- Repeating headers are retained as arrays in JSON.
- Sensitive values such as Authorization are not saved or uploaded, and it is recommended to clear them immediately after use.
How to use it
- Paste the HTTP Header text.
- Click "Parse Headers".
- Check for tables, duplicate fields, and parsing errors.
- Copy the JSON and clear sensitive input.
Common uses
- Analyze the request header copied by the browser development tool.
- Check for duplicate Set-Cookie or multi-valued headers.
- Collate the header text into test fixture JSON.
Privacy and security
The header text will not be sent to any address, and sensitive fields such as Authorization will not be saved.
HTTP Header Parser Features
Parses plain text HTTP headers, preserving colons in repeated fields and values, and outputs JSON. Useful for everyday development and debugging; results can be reviewed, copied, or downloaded immediately.
FAQ
Will it be lost if there is a colon in the value?
No. The parser splits only the first colon, leaving the remaining colons in Value.
Will duplicate headers be overwritten?
No, fields with the same name are left intact and represented as arrays in JSON.
Will the tool request the target website to obtain the header?
No, it only parses the text you pasted.
Will the Authorization be saved?
No. The page does not persist or upload input, but you should still be careful when handling real credentials and clear them promptly.