# HTTP Header Parser Guide

Turn a pasted header block into a clean table, including cookies and repeated fields.

- Tool: https://ilham.dev/tools/http-header-parser/
- Guide URL: https://ilham.dev/guides/http-header-parser/
- Tool guides index: https://ilham.dev/guides/tools/
- Broader guide: HTTP and API Debugging (https://ilham.dev/guides/http-api-debugging/)

## What it does

Paste a raw header block from curl, a proxy log or the browser network panel and the page turns it into a clean table. A status line is optional, folded continuation lines are rejoined, and repeated fields such as Set-Cookie are kept and marked so nothing is silently dropped.

## Use the tool

Open https://ilham.dev/tools/http-header-parser/, add the input the tool asks for, run it, and check the output before using it elsewhere.

## Input and output

- Input: text.
- Output: text.
- Category: Network.

## Privacy and processing
Processing happens locally in your browser. This tool does not upload the input to ilham.dev.

## Questions

### Why are some headers marked as repeated?

Because the same field name appears more than once. Some headers, like Set-Cookie, are supposed to repeat and must not be merged; others are combined by the recipient. The label shows you which is which before you act on the values.

### How are folded lines handled?

Older systems wrapped long header values onto the next line with leading whitespace. The parser treats a line that starts with a space or tab as a continuation of the previous header and joins it back with a single space, which is what the HTTP rules say to do.

### What is the status line?

The HTTP/1.1 200 OK line that opens a response. It is optional here, so you can paste just the headers, but when it is present it is reported separately and not mistaken for a header.

### Is anything sent over the network?

No. The text you paste is parsed in the page. That is deliberate: header blocks often carry cookies, tokens and internal hostnames that should not leave your machine.