Create short, trackable URLs with detailed click analytics. Track visitor location, devices, referrers, and more. Password protection & QR codes included.
Generate a unique URL to easily test, receive and inspect HTTP webhooks in real-time. View request headers, query parameters, JSON payloads, and more.
Look up A DNS records for any domain and verify IPv4 address mapping with TTL values. Instantly check DNS A record propagation and IP assignments.
Look up AAAA DNS records for any domain and verify IPv6 address mapping with TTL values - free, browser-based, no data stored.
Accept-Language parser that ranks browser locales by q-value. Parse the header, spot duplicates and match it against your supported locales. Free.
Check BIMI DNS records and parse logo and authority directives to validate brand indicator setup for email clients - free to use.
Look up browser and HTTP error codes - ERR_SSL_VERSION_OR_CIPHER_MISMATCH, 502 Bad Gateway, ERR_NAME_NOT_RESOLVED, and more. See causes and step-by-step fixes.
See live browser details including user agent, platform, language, screen size, viewport, online status, and device capabilities.
Check a domain's CAA DNS records to see which certificate authorities can issue SSL certificates - free tool, no account required.
Check CNAME DNS alias records for subdomains and verify canonical host targets. Useful for debugging CDN, custom domains, and subdomain redirects.
Common ports lookup: search 96 well-known TCP and UDP ports by number or service name. Shows whether each port is safe to expose to the internet and why not. Works offline.
CORS tester checks whether a URL allows cross-origin requests from your browser, and explains exactly why a request was blocked when it fails. Free, no signup.
Check DKIM TXT records by selector and domain to verify email signing configuration and public key tags - no signup required.
Check and parse the DMARC DNS TXT record for any domain to verify email authentication policy, alignment settings, and reporting addresses.
Look up DNS records for any domain. Query A, AAAA, CNAME, MX, NS, TXT, and SOA records instantly using Google Public DNS. Essential for domain troubleshooting.
Check DNS propagation across global resolvers for A, AAAA, CNAME, MX, NS, and TXT records to confirm your DNS changes have spread.
Query DNSKEY records for any domain and inspect DNSSEC public key metadata including flags, protocol, and algorithm - runs in your browser.
Parse raw email headers to trace routing path, verify SPF and DKIM authentication, detect delays, and debug email delivery issues.
gRPC status code lookup explains all 17 codes with HTTP mapping, retry guidance and language constants. Paste a code, a name or a log line. Free.
Parse raw HTTP request or response headers into a readable table, JSON structure, and quick audit view for security, caching, and CORS.
Inspect all HTTP response headers of any website. Audits security headers like HSTS, CSP, and X-Frame-Options and groups headers by type.
Free URL status and HTTP response checker. See the status code, response headers, every 301/302 redirect hop and the response time for any link. No signup.
Look up any HTTP status code and its meaning instantly, from 200 OK and 404 Not Found to 500 Server Error. Browse or search the list free, no signup required.
Test if any website supports HTTP/2 and HTTP/3 (QUIC) via real TLS ALPN negotiation. Shows TLS version, server headers, alt-svc advertisement, and response time.
Test your internet speed online. Measure download speed, upload speed, ping, and jitter instantly in your browser using Cloudflare's servers.
Look up geolocation, ISP, timezone, and other information for any IP address. Find your public IP and trace IP locations instantly.
Check if an IP address is listed on 15+ major DNSBL spam blacklists including Spamhaus, SpamCop, and Barracuda. Instantly audit email server reputation and identify deliverability issues.
Instantly look up the geographic location, ISP, timezone, and network details for any IP address. Enter an IP or detect your own public IP with one click.
IP range to CIDR converter that turns a start and end address into the smallest exact set of CIDR blocks. Merges overlapping ranges, handles IPv4 and IPv6. Free, no signup.
IPv6 address expander converts shorthand IPv6 to the full 8-group form and compresses it back to RFC 5952 canonical notation. Keeps CIDR, zone IDs and embedded IPv4.
Look up what runs on any localhost port, open it in one click, and understand localhost vs 127.0.0.1. Covers 20+ dev ports including React, Vite, Ollama, Python, and databases.
Look up the manufacturer or vendor of any network device from its MAC address OUI prefix. Identifies device maker, unicast/multicast type, global/local scope, and randomised MAC detection for iOS and Android.
Validate MTA-STS TXT records for any domain and review policy ID metadata for SMTP transport security - browser-based, no install needed.
Look up MX DNS records for any domain to see which mail servers handle incoming email and their priority - free, no signup needed.
Look up authoritative NS records for any domain and verify nameserver delegation with TTL details in one fast DNS query.
PCAP viewer that opens .pcap and .pcapng captures in your browser. Decodes TCP, UDP, DNS, HTTP and TLS, with Wireshark-style filters. Never uploaded. Free.
Test HTTP latency to a public website with repeated ping attempts, average response time, jitter, and request-failure tracking.
Check if a specific port is open or closed on any host or IP address. Test TCP connectivity for common service ports like HTTP, SSH, MySQL, and more.
Perform a reverse DNS PTR lookup for any IPv4 or IPv6 address to find its mapped hostname. Useful for server audits, email deliverability, and IP reputation checks.
Analyze API rate limit headers instantly to see remaining quota, reset countdown, and usage percentage. Supports X-RateLimit, RateLimit, and Retry-After.
Trace the full redirect chain for any URL. See every HTTP hop, status code, and final destination to debug SEO, link shorteners, and site migrations.
Check which HTTP security headers are present on any website and get an instant A+ to F grade. Verifies Content-Security-Policy, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy, COOP, and CORP.
Check SOA DNS records for any domain and inspect serial, refresh, retry, expire, and minimum TTL - instant results, no install required.
Validate SPF DNS records for any domain and review include chains, mechanisms, and all-policy qualifiers to debug deliverability issues.
Look up SRV DNS records and inspect priority, weight, port, and target host values for service routing validation - no signup needed.
Check SSL certificate details for any domain - expiry date, issuer, Subject Alternative Names, TLS version, and fingerprint. Instantly verify if a certificate is valid, trusted, and how many days remain before it expires.
Subnet calculator computes IPv4 network masks, broadcast addresses, and host ranges from any IP and CIDR prefix - fast, free, and works entirely in your browser.
Check TLS-RPT DNS records and inspect report destination URIs to monitor SMTP TLS delivery failures - free tool, no signup required.
Look up TXT DNS records for SPF, domain verification, and email authentication tokens with instant results and clean JSON output.
Check URL redirect chains, final destination URL, and HTTP status codes for any link to debug SEO migrations and shortened URLs.
Expand shortened URLs from bit.ly, t.co, tinyurl, and others to reveal the final destination and full redirect chain - free tool.
VLSM calculator that splits one network into right-sized subnets from your host counts. Shows CIDR, mask, host ranges, broadcast and wasted IPs. Free.
Check if a website is down for everyone or just you. Test website availability, status code, DNS resolution, and response time from an independent server.
Detect the technology stack behind any website - CMS, JavaScript frameworks, analytics, CDN, hosting, and 80+ more technologies fingerprinted from HTTP headers and HTML source.
WebSocket tester connects to any ws:// or wss:// endpoint, sends messages, and logs responses in real time. Free, browser-based WebSocket client for debugging APIs.
Look up domain registration details including registrar, creation date, expiry date, nameservers, and status flags for any public domain.
Wildcard mask calculator that converts between CIDR, subnet mask and Cisco ACL wildcard bits, and flags non-contiguous masks. Free, no signup.
Generate WireGuard server and client configs with fresh key pairs, preshared keys and QR codes for mobile. Full or split tunnel. Keys stay in your browser.