HTTP Header Viewer
View HTTP response headers for any URL.
HTTP response headers reveal caching policies, security settings, server software, redirects, and content types. Utilitoo's HTTP Header Viewer fetches any public URL and displays the full response header table along with status code and final URL after redirects.
Developers debug CORS and cache-control issues, SEO professionals audit redirect chains, and security teams verify HSTS, CSP, and X-Frame-Options headers on production sites. Localization and support teams often need the request-side Accept-Language chain from a ticket instead - paste that header into Locale Converter to get BCP 47 and POSIX tags.
Enter a URL and click Fetch headers. The tool tries HEAD first and falls back to GET if needed. Headers are sorted alphabetically for easy scanning. Pair with DNS Lookup to verify domain resolution, User Agent Parser for the User-Agent header, or Locale Converter when the interesting header is Accept-Language.
Requests are made server-side to avoid browser CORS restrictions. Private and local network addresses are blocked for safety. Free for developers and ops teams.
HTTP Header Viewer parses and displays header names and values from pasted HTTP traffic. It helps developers read what browsers and APIs already returned. Group cache, security, and content headers mentally while reading a dump so misconfigurations stand out. If you paste production headers, redact cookies and tokens first even though Utilitoo keeps processing local.
Common use cases
- Inspecting sample response headers pasted from DevTools.
- Teaching cache-control and content-type headers in workshops.
- Reviewing security headers on a staging response dump.
- Comparing header sets before and after a CDN change.
- Preparing documentation examples of canonical response headers.
Tips & common mistakes
Paste raw header blocks carefully - missing colons break parsing. This viewer does not fetch live URLs by itself unless the UI offers a request feature. Pair with HTTP Status Codes for status line context. Accept-Language values are locale tags, not cache policy - convert them in Locale Converter. Normalize header names to lowercase mentally when comparing HTTP/2 traces with classic HTTP/1.1 dumps. Remove set-cookie values from screenshots that leave your machine. Use Mime Type Lookup when Content-Type values look unfamiliar.
Common errors
- Including the HTML body in the paste confuses header parsing.
- HTTP/2 pseudo-headers need different mental models than classic Name: value lines.
How to use
- Enter a URL.
- Click Fetch headers.
- Review status and header table.
Frequently Asked Questions
Why use a header viewer instead of browser DevTools?▼
Server-side fetching avoids CORS limits and shows headers for any public URL without opening the site. For Accept-Language tags from a ticket rather than a live URL, convert them in Locale Converter.
Are private URLs allowed?▼
No. Localhost, private IP ranges, and internal hostnames are blocked to prevent abuse.
HEAD or GET request?▼
HEAD is tried first for efficiency. GET is used automatically if the server rejects HEAD.
Do redirects show the final URL?▼
Yes. The response shows the final URL after following redirects.
Is the URL stored?▼
No. Utilitoo does not log fetched URLs.
Related Tools
DNS Lookup
Look up DNS records for any domain.
URL Encoder / Decoder
Encode and decode URL strings and query parameters.
User Agent Parser
Parse browser user agent strings.
Locale Converter
Convert BCP 47, POSIX, and Accept-Language locale strings.
HTTP Status Codes
Searchable reference for common HTTP status codes.
MIME Type Lookup
Look up MIME types by extension or media type.