HTTP Header parsing

Parse local Header text, preserving original field names, duplicate fields, normalized mappings, and control-character warnings.

Local browser processing
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User Guide

How to use HTTP Header parsing

HTTP Header parsing processes input only in the current browser; it does not upload data, connect to the internet, or write to persistent storage.

  1. Input Header

    Edit the default Content-Type, duplicate Cache-Control, Set-Cookie, and malformed-line examples.

  2. Parse fields

    View line numbers, original field names, normalized names, duplicate values, and warnings.

  3. Copy report

    Export the parsed result; the tool does not send or validate HTTP requests.

Limitations and Notes

  • Does not check the server’s actual response or request the URL shown in the Header.
  • Line breaks, control characters, and excessively long fields are displayed as warnings or errors.
  • The parsing result cannot replace actual behavior verification with the target server, proxy, and browser.

FAQ

Will duplicate headers be merged?

The tool preserves the original order and values while also providing a normalized array mapping.

Will it send requests?

No, the input is used only as local text.

Why are erroneous lines still displayed?

Preserving the error context helps locate the problem in the original header.

Page feedbackFound an issue or have suggestions for improvement?
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