Utilities

HTTP Header Parser

Parse and analyze HTTP request and response headers

Raw HTTP Headers

About

Parses HTTP request and response headers with automatic categorization into request, response, entity, and general headers. Includes a security audit that flags missing security headers (like CSP, HSTS, X-Frame-Options), a header builder for constructing custom headers, and cURL/Fetch export of the header configuration. Validates header syntax against RFC standards.

Debugging HTTP headers manually is tedious and security issues like missing CSP or HSTS headers are easy to overlook. This tool centralizes header inspection, security auditing, and code generation in one place to streamline web development and security analysis.

Who should use this tool?

Web developers debugging API responses, security engineers auditing HTTP security headers, and QA engineers testing server configurations.

Common use cases

Parse response headers from a cURL command output to understand the server configuration
Run a security audit on your API's response headers to identify missing security protections
Build a custom set of HTTP headers using the builder and export as a cURL command
Validate a custom header string for RFC compliance before adding it to a server config
Copy the parsed headers as a Fetch API call with headers included for testing in the browser console

How to Use

Paste raw HTTP headers (from browser dev tools, cURL -v output, or server logs) into the input area

View the categorized output: each header is grouped as request, response, entity, or general

Click the Security Audit button to scan for missing security headers; results highlight what is absent and provide recommendations

Use the Header Builder tab to construct headers manually with key-value pair inputs

Export the header set as a cURL command or a Fetch API JavaScript snippet

Header validation is automatic; invalid headers are flagged with an explanation of the RFC violation

Examples

Input: 'Content-Type: text/html\nX-Frame-Options: DENY\nStrict-Transport-Security: max-age=31536000' categorized as entity/response/response with security audit showing HSTS present, CSP missing.

Input: 'Content-Type: application/json' built in Header Builder, exported as Fetch: 'fetch(url, {headers: {"Content-Type": "application/json"}})'

Best Practices

Run the security audit against all your API endpoints to ensure consistent security header coverage
Use the builder to standardize headers across microservices and export as shared config
Always validate custom headers before adding them to production server configurations
Export to cURL when sharing reproductions of header-related issues with colleagues

Common Mistakes

Pasting headers with line breaks that don't follow HTTP/1.1 CRLF format, causing parse errors
Assuming the security audit covers all possible security headers; it covers the OWASP recommended set
Using the builder but forgetting to include required headers like Content-Type or Host
Exporting to Fetch without checking if the target environment supports the generated syntax

FAQ

What security headers does the audit check? It checks CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and more.

Can I parse headers from a HAR file? Yes, extract the headers section from the HAR JSON and paste them.

Does it support HTTP/2 pseudo-headers? Yes, :method, :path, :scheme, :authority are parsed correctly.

Can I export as Python requests code? Currently supports cURL and Fetch export; Python coming soon.

Related Tools

Same Category — Utilities

Word Counter

Count words, characters, sentences, and analyze text readability with Flesch scores

Regex Tester

Test and debug regular expressions with real-time matching, capture groups, and extended flags

Markdown Preview

Live preview and edit Markdown with syntax highlighting

IP Address Calculator

Calculate subnet masks, CIDR notation, and IP ranges

Popular Tools

JSON Formatter

Format, validate, and minify JSON data with syntax highlighting

Base64 Encoder/Decoder

Encode and decode Base64 strings online free

JWT Decoder

Decode and analyze JWT tokens online free

Learning Resources

Dive deeper with our comprehensive guides and tutorials.

HTTP Header Parser - Beginner's Guide

5 min read

HTTP Header Parser Advanced Techniques

8 min read

About

Who should use this tool?

Web developers debugging API responses, security engineers auditing HTTP security headers, and QA engineers testing server configurations.

Common use cases

Parse response headers from a cURL command output to understand the server configuration
Run a security audit on your API's response headers to identify missing security protections
Build a custom set of HTTP headers using the builder and export as a cURL command
Validate a custom header string for RFC compliance before adding it to a server config
Copy the parsed headers as a Fetch API call with headers included for testing in the browser console

How to Use

Paste raw HTTP headers (from browser dev tools, cURL -v output, or server logs) into the input area

View the categorized output: each header is grouped as request, response, entity, or general

Click the Security Audit button to scan for missing security headers; results highlight what is absent and provide recommendations

Use the Header Builder tab to construct headers manually with key-value pair inputs

Export the header set as a cURL command or a Fetch API JavaScript snippet

Header validation is automatic; invalid headers are flagged with an explanation of the RFC violation

Examples

Input: 'Content-Type: text/html\nX-Frame-Options: DENY\nStrict-Transport-Security: max-age=31536000' categorized as entity/response/response with security audit showing HSTS present, CSP missing.

Input: 'Content-Type: application/json' built in Header Builder, exported as Fetch: 'fetch(url, {headers: {"Content-Type": "application/json"}})'

Best Practices

Run the security audit against all your API endpoints to ensure consistent security header coverage

Use the builder to standardize headers across microservices and export as shared config

Always validate custom headers before adding them to production server configurations

Export to cURL when sharing reproductions of header-related issues with colleagues

Common Mistakes

Pasting headers with line breaks that don't follow HTTP/1.1 CRLF format, causing parse errors

Assuming the security audit covers all possible security headers; it covers the OWASP recommended set

Using the builder but forgetting to include required headers like Content-Type or Host

Exporting to Fetch without checking if the target environment supports the generated syntax

FAQ

What security headers does the audit check? It checks CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, and more.

Can I parse headers from a HAR file? Yes, extract the headers section from the HAR JSON and paste them.

Does it support HTTP/2 pseudo-headers? Yes, :method, :path, :scheme, :authority are parsed correctly.

Can I export as Python requests code? Currently supports cURL and Fetch export; Python coming soon.

HTTP Header Parser

About

Who should use this tool?

Common use cases

How to Use

Examples

Best Practices

Common Mistakes

FAQ

Related Tools

Same Category — Utilities

Word Counter

Regex Tester

Markdown Preview

IP Address Calculator

Popular Tools

JSON Formatter

Base64 Encoder/Decoder

JWT Decoder

Learning Resources

Share

HTTP Header Parser

About

Who should use this tool?

Common use cases

How to Use

Examples

Best Practices

Common Mistakes

FAQ

Related Tools

Same Category — Utilities

Word Counter

Regex Tester

Markdown Preview

IP Address Calculator

Popular Tools

JSON Formatter

Base64 Encoder/Decoder

JWT Decoder

Learning Resources

Share