HTTP Header Parser

The HTTP Header Parser takes a block of raw HTTP headers copied from a request or response and turns it into a clean, readable table. Each header is split into its name and value, folded continuation lines are rejoined, and any request or status line is skipped, so you get an orderly list rather than a wall of text. It is the quickest way to make sense of headers pasted from a browser's network tab or a command-line client.

To help you interpret what you are looking at, the parser adds a short note for many common headers, explaining at a glance what Content-Type, Cache-Control, Authorization, Set-Cookie, Strict-Transport-Security, and dozens of others actually do. This turns a raw dump into a teaching tool, which is especially useful when you are debugging caching, CORS, security policies, or authentication and want to confirm each header is doing its job.

Parsing runs entirely in your browser, so the headers you paste, which may include cookies or tokens, are never uploaded or stored. That keeps sensitive request and response data private while you inspect it. The tool is free and instant, and it reports how many headers it found, so you can quickly confirm nothing was missed.

Features

• Splits each header line into a clean name and value pair in a sortable table.
• Skips the request line or status line so only real headers are listed.
• Rejoins folded headers whose values continue on an indented following line.
• Adds explanatory notes for many common request and response headers.
• Stops at the first blank line so a pasted body does not pollute the results.
• Reports the total number of headers parsed for a quick completeness check.
• Runs fully in your browser and exports the table to copy, CSV or spreadsheet.

How to use HTTP Header Parser

1. Copy the raw headers from your browser's network tab or a command-line client.
2. Paste them into the input box, including any request or status line.
3. Read the parsed table of header names and values.
4. Check the notes column to understand what each common header does.
5. Use the header count to confirm every line was captured.
6. Export the table to CSV or a spreadsheet if you need to share it.

Benefits

• Developers debug caching, CORS and security headers without eye-straining raw text.
• The notes column teaches what unfamiliar headers control while you work.
• QA engineers verify that expected headers are present and correctly valued.
• Support teams share a tidy table of headers instead of a messy paste.
• Folded and continuation lines are handled so long values read correctly.
• Local parsing keeps cookies, tokens and other sensitive headers private.

HTTP headers are simple in principle, a name followed by a colon and a value, but in practice a raw capture is easy to misread. It often begins with a request line such as a GET line or a status line, values can be long, and older formats allow a header to fold across multiple indented lines. This parser normalizes all of that, so you can paste exactly what you copied and get a consistent table without hand-editing the text first.

The notes are intended as quick reminders rather than a full specification, covering the headers you meet most often when building and debugging web applications. Security-related headers like Content-Security-Policy, X-Frame-Options, and Strict-Transport-Security get short explanations because they are easy to misconfigure, while caching headers like Cache-Control, ETag, and Last-Modified are annotated to help you reason about why a response is or is not being reused.

Because everything runs locally in your browser, there is no upload and no logging, which matters a great deal when headers contain Authorization tokens or Set-Cookie values. Parsing stops at the first blank line, so if you paste a full raw response the body is ignored and only the headers are shown. Treat the notes as guidance and consult the official specifications when you need precise, authoritative detail.