HTTP Header Parser Guide

Request and response headers arrive as colon-separated text, and several names can appear more than once. Turning that block into structured data makes cache, content type, security, and negotiation behavior easier to review.

How to use the HTTP Header Parser

1. Paste the header block without the response body.
2. Run the parser to normalize names and group duplicate fields.
3. Copy the JSON into a diagnostic note or compare it with the expected server configuration.

A practical example

Two Vary header lines are retained as two values. This matters because a cache that ignores one of them can serve the wrong representation even though the raw response looked plausible.

The HTTP Header Parser runs locally in the browser, so the input is available for the calculation without being uploaded by this tool.

Checks before you use the output

• Header names are case-insensitive, but values are not always interchangeable.
• Do not split values on commas unless the specific header grammar permits it.
• Remove authorization cookies and tokens before sharing parsed output.

Use the result as part of a review

Convert raw HTTP header lines into grouped JSON. The output is designed to make a small task faster, but it should still be checked against the requirements of the destination system, document, or decision.

Privacy and safe sample data

Processing happens in the current browser tab. Even so, remove passwords, authorization values, customer records, and other confidential data before copying results into chat, tickets, or public examples.