Free HTTP Headers Parser

The HTTP Headers Parser is a free online tool that parse and analyze http headers from requests and responses. It runs entirely in your browser with no installation or sign-up needed.

Yes, it is completely free with no registration required. All parsing happens client-side in your browser.

The HTTP Headers Parser displays each header name and value with explanations of security implications, caching behavior, and content negotiation.

Absolutely. The HTTP Headers Parser processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the HTTP Headers Parser is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the HTTP Headers Parser in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

The HTTP Headers Parser supports a wide range of popular formats and languages. Check the tool interface for the full list of supported options.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The HTTP Headers Parser works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

The parser audits ten weighted security headers and converts the result into a 0-100 score with a letter grade. Content-Security-Policy carries the most weight, followed by Strict-Transport-Security, while clickjacking and MIME-sniffing protections like X-Frame-Options and X-Content-Type-Options sit just behind them. Each header is checked as pass, warning, or missing: a present, well-configured header earns full points, a weak value earns partial credit, and a missing one earns none. The totals map to a grade where 90 and above is A+, 80 is A, 70 is B, 60 is C, 50 is D, and anything lower is F. This mirrors the grading approach used by industry tools but runs entirely in your browser. Paste your response headers above to see your score, grade, and exactly which checks passed.

Request headers are sent by the browser or client to the server and describe the request itself: who is asking, what content they accept, and the context. Examples include Host, User-Agent, Accept, Authorization, and the Sec-Fetch family. Response headers are sent back by the server and describe the reply and how the client should treat it, covering Content-Type, Cache-Control, Set-Cookie, and security headers like Content-Security-Policy and Strict-Transport-Security. Some headers, such as Content-Type, appear in both directions with slightly different meanings. The distinction matters because security scoring and missing-header checks only apply to responses, while request analysis is about debugging what the client sent. This tool lets you switch between Request and Response mode so the categorization and warnings match exactly what you are analyzing. Paste your block above and pick the matching mode.

The parser inspects each Set-Cookie value and warns when it is missing protective attributes. A cookie without HttpOnly can be read by JavaScript, which exposes it to cross-site scripting theft; without Secure it can travel over plain HTTP; and without SameSite it is more vulnerable to cross-site request forgery. Session and authentication cookies should almost always carry all three, for example HttpOnly; Secure; SameSite=Strict. The warning is a nudge, not an error, since a few cookies legitimately need to be readable by scripts, but for anything tied to login or identity the flags are best practice. The tool surfaces these issues inline as it parses so you can fix the header before shipping. Paste your Set-Cookie line above to see which attributes are present and which are recommended additions.

The widely accepted baseline is max-age=31536000; includeSubDomains, which tells browsers to use HTTPS for one full year (31,536,000 seconds) across the domain and all of its subdomains. Adding preload on top of that makes the domain eligible for the browser preload list, which hard-codes HTTPS so the very first visit is protected too. The parser scores HSTS as a full pass only when the max-age is at least one year and includeSubDomains is present; a shorter max-age earns a warning, and a missing header fails. Be cautious with includeSubDomains and preload, since they apply to every subdomain and are slow to undo, so confirm all subdomains support HTTPS first. The tool gives you a copy-ready recommended value and flags whether your current header qualifies for preload. Paste your headers above to check it.

A Content-Security-Policy restricts where scripts, styles, and other resources can load from, which is one of the strongest defenses against cross-site scripting. The keywords 'unsafe-inline' and 'unsafe-eval' punch holes in that defense: 'unsafe-inline' allows inline scripts and styles written directly in the page, and 'unsafe-eval' permits eval-style execution of strings as code, both of which attackers can abuse. Because they weaken protection, the parser still counts a CSP that contains them as present but downgrades it to a warning rather than a full pass. The stronger pattern is to remove them and allow only trusted sources, often using nonces or hashes for any inline code you genuinely need. The tool detects these keywords as it parses and explains the impact. Paste your CSP header above to see whether it passes cleanly or triggers a warning.