HTTP status codes, MIME types, headers, User-Agent parser.
Search all HTTP status codes with descriptions.
Find MIME types by extension or name.
Parse any User-Agent string.
Break a URL into its components.
Inspect IPv4/IPv6 addresses.
A, AAAA, MX, TXT, CNAME records.
Preflight any endpoint from the browser.
Check security headers of any URL.
Validate a robots.txt file.
Simulate Apache redirect rules.
GET / POST / PUT / PATCH / DELETE — semantics, idempotency, safety.
Searchable list of standard request and response headers.
Cookie attribute cheatsheet — Secure, HttpOnly, SameSite.
Paste a status code, get meaning + retryability + common causes.
Assemble a URL from protocol / host / path / query / fragment.
Validate a URL against RFC 3986.
Build ?key=value query strings with proper encoding.
Compose a custom User-Agent string for any browser.
Browse common UAs for browsers, bots and crawlers.
Inspect your browser's navigator, screen, viewport and feature flags.
Detect local and public IPs leaked through WebRTC.
Resolve an IP back to a hostname (PTR record via DoH).
Inspect DNSSEC RRSIG / DS records via Cloudflare DoH.
Build a Content-Security-Policy header visually.
Build the Access-Control-* headers for a given policy.
Build the Cache-Control header with proper directives.
Build a Strict-Transport-Security header with preload-friendly defaults.
Generate a complete <head> meta-tag package.
Build og:title / og:image / og:description tags with preview.
Build twitter:card tags with live preview.
Generate hreflang link tags for multilingual sites.
Build JSON-LD for Article / Product / FAQ / Recipe / Event.
Build canonical and alternate link tags.
Build a robots.txt with User-agent / Allow / Disallow / Sitemap rules.
Build a sitemap.xml from a URL list.
Validate a sitemap.xml against the sitemaps.org spec.
Generate Apache redirect / rewrite / auth blocks visually.
Generate Apache basic-auth credential lines (bcrypt / MD5).
Build nginx location and rewrite blocks.
Build a Sender Policy Framework TXT record.
Build a DKIM DNS TXT record from a public key.
Build a DMARC TXT record with policy and reporting.
Format MX records with proper priorities.
Build manifest.json for a PWA with icons and theme.
Generate a service worker (cache-first / network-first / SWR).
Build preload / prefetch / preconnect / dns-prefetch tags.
Connect to a ws:// or wss:// endpoint and exchange messages.
Visual HTTP request constructor — like Postman in the browser.
Search the IANA list of top-level domains (gTLDs, ccTLDs).
Quick answers to the questions developers ask most.
Switch context — 11 more toolsets ready to go.