Tools that look up DNS. check a certificate. read response headers. decode a JWT.

Query A, AAAA, MX, TXT, NS, CNAME, SOA and more. Fast server-side resolution.

Compare DNS answers from public resolvers worldwide to spot stale or partial propagation.

WHOIS for domains and IPs. .gr/.ελ via official FORTH registry; country TLDs (.de, .uk, .fr, .nl, .eu, …) use the right registry server. Batch up to 12.

Check SPF, DMARC and DKIM records for a domain. Useful for email deliverability.

Build a valid SPF TXT record from includes, IPs, and policy — copy into DNS.

Build a DMARC TXT record for _dmarc with policy, reporting URI, and alignment options.

List MX hosts and priorities for a domain — quick mail routing checks.

See your public IP, geolocation, ASN, ISP and incoming HTTP headers.

Lookup any IP address for location, ASN, organization and reverse DNS.

Find the hostname(s) associated with an IP address.

Check a site for important security headers (HSTS, CSP, X-Frame-Options, etc.).

Decode JWT header and payload (no signature verification). For debugging tokens only.

Estimate entropy and common-pattern risk. Runs entirely in your browser.

Generate cryptographic hashes. Useful for verification and integrity checks.

Format, validate and minify JSON. Still one of the most used dev tools.

Encode or decode Base64 text in the browser.

Percent-encode or decode URI components safely.

Generate random UUIDs for IDs, correlation tokens, and test data.

Generate random passwords with configurable length and character sets.

Convert between Unix timestamps and human-readable dates (UTC).

Parse standard 5-field cron syntax into plain English schedule hints.

Convert between HEX and RGB color values with a live preview.

Switch text between upper, lower, title, and snake_case styles.

Count words, characters, and lines in any text block.

Fetch and inspect all response headers from any URL. Great for debugging.

Probe whether a host speaks HTTP/2 or HTTP/1.1 over TLS with curl.

Check certificate chain, expiry, SANs, issuer and validity for any domain.

Follow HTTP redirects and see the full chain with status codes and locations.