HTTP Header Parser — Free Online HTTP Headers Checker & Analyzer

HTTP Header Parser — Free Online HTTP Headers Checker & Analyzer. Free online HTTP header parser and checker.

Paste raw HTTP request or response headers to instantly parse them into a clean table and JSON — works with curl headers, API responses, and server logs. Our free HTTP header parser instantly converts raw HTTP headers into a structured table and JSON output.

Paste headers from curl, browser DevTools, or API responses to quickly check and analyze every key-value pair.

Use Cases Debug API responses by inspecting response headers Check security headers like Content-Security-Policy and X-Frame-Options Analyze CORS headers to troubleshoot cross-origin issues Parse curl headers output into readable JSON Verify caching headers like Cache-Control and ETag Related: HTTP Status Codes , User Agent Parser , cURL Generator .

Frequently asked questions

How do I parse raw HTTP headers?

Paste headers, one per line in Name: Value form, into the Input HTTP Headers box. The Parsed Headers table lists each header and its value with the status line on top, and a JSON version appears under the input with a Copy JSON button.

How do I get the headers of a URL to paste here?

Run curl -I followed by the URL to print only the response headers, then paste the output. You can also copy request or response headers from the Network tab of your browser's developer tools. This tool does not fetch URLs itself; it only parses the text you paste.

What do the lock icon and green highlight mean?

They mark security headers: Content-Security-Policy, Strict-Transport-Security, X-Frame-Options, X-Content-Type-Options, X-XSS-Protection, Referrer-Policy, Permissions-Policy and the Cross-Origin Opener, Resource and Embedder policies. The badge counts those present; missing ones are not flagged.

Which header formats can I paste?

Response headers starting with a status line such as HTTP/1.1 200 OK or HTTP/2 200, request headers starting with a line like GET /path HTTP/1.1, or plain header lines with no first line. Blank lines are ignored and indented continuation lines without a colon are joined to the previous header.

Why is a repeated header shown only once in the JSON?

The JSON output is an object keyed by header name, so when a header such as Set-Cookie appears several times only the last value is kept there. The Parsed Headers table still lists every occurrence.

How to use this online tool

HTTP Header Parser — Free Online HTTP Headers Checker & Analyzer is designed for fast browser workflows when you need to format, validate, convert, decode, encode, generate, or inspect data without opening a heavy desktop app. Start with the input field or visible options, review the result, then copy or download the output for the next step.

Private processing in your browser

HTTP Header Parser — Free Online HTTP Headers Checker & Analyzer keeps the normal processing step local in your browser. That is useful for code snippets, tokens, documents, configuration values, text samples, and other material that should not be sent to a remote service unless you explicitly choose to share it.

When this tool is useful

Use HTTP Header Parser — Free Online HTTP Headers Checker & Analyzer for repeatable developer tasks, technical documentation, QA checks, quick conversions, debugging, content cleanup, and internal team workflows. The page focuses on clear inputs, immediate feedback, and output that is easy to reuse in code, reports, tickets, emails, or notes.

Practical tips

Before copying the final result, check important details such as spacing, casing, filenames, encoding, token structure, line breaks, or output format. Small checks prevent mistakes when the result is reused in source code, API requests, documentation, spreadsheets, or shared files.