Directory of Tools
Browse all 85+ production-grade DNS, networking, email deliverability, and developer tools. Fast, free forever, no signup required.
DNS
21Propagation Checker
Query 20+ global DNS resolvers in parallel.
DNS Lookup
Look up any DNS record type for a domain.
DNS Trace
Root → TLD → Authoritative iterative resolution trace.
NS Lookup
Find authoritative nameservers.
MX Lookup
Mail exchange servers and priority.
CNAME Lookup
Resolve CNAME aliases.
Reverse DNS
IP → hostname (PTR).
Domain → IP
Resolve A / AAAA records.
Subdomain Finder
Enumerate subdomains via CT logs.
CAA Lookup
Which CAs can issue TLS certs for a domain.
SOA Lookup
Zone serial, refresh, retry, expire timers.
TXT Lookup
All TXT records — SPF, DKIM, DMARC & verification tokens.
SRV Lookup
SIP, XMPP, Matrix, Minecraft & custom SRV records.
DNSSEC Checker
DS, DNSKEY & chain-of-trust validation.
HTTPS / SVCB Lookup
RFC 9460 service binding — ALPN, ECH, IP hints.
TLSA / DANE
TLS certificate association records (DANE).
NAPTR Lookup
ENUM & SIP URI service discovery.
Wildcard Checker
Detect *.domain wildcard DNS records.
IPv6 Readiness
AAAA coverage on web, mail & DNS — graded A–F.
All Records
Bulk lookup — 12 record types in one query.
Email Provider
Detect Google, M365, Zoho + SPF senders.
Domain
5Email deliverability
9Spam Score Checker
0–100 deliverability audit for SPF, DMARC & MX.
SPF Checker
Parse & validate SPF record.
DMARC Checker
Parse & validate DMARC policy.
DMARC Generator
Build a DMARC TXT record.
DKIM Checker
Query DKIM public key for a selector.
BIMI Checker
Look up BIMI record and logo.
Email Headers
Parse raw email headers & delivery hops.
IP Blacklist
Check IP against 20+ DNSBL zones.
MTA-STS & TLS-RPT
SMTP TLS enforcement (RFC 8461) + reporting.
IP & Network
8IP Lookup
Geo, ASN, ISP, org for any IP.
Open Port Checker
Check open ports (22, 80, 443, 3306, 5432).
What is my IP
See your public IP, ISP, geo.
What is my ISP
See your ISP and connection info.
User Agent
Parse your browser & OS.
ASN Lookup
AS number, prefixes, peers.
Subnet Calculator
CIDR, mask, hosts, ranges.
IP Converter
IPv4 ↔ IPv6, decimal, hex, binary.
Web & HTTP
9HTTP Status Codes
Interactive 1xx–5xx codes & Cloudflare edge errors.
HTTP Headers
Response headers, status, TLS.
Redirect Checker
Follow the redirect chain.
SSL Checker
TLS cert issuer, validity, SANs.
CT Search
Every TLS cert ever issued for a domain (crt.sh).
Security Headers
Grade HSTS, CSP, X-Frame-Options A–F.
CMS Detector
Detect WordPress, Shopify, etc.
Robots.txt Generator
Build a robots.txt file.
Sitemap Generator
Generate a sitemap.xml.
Developer
17YAML ↔ JSON
Convert & validate YAML and JSON configs.
Base64 Converter
Image & file to Base64 and Data URI generator.
Markdown Table
Visual editor for Markdown & HTML tables.
Color Converter
HEX ↔ RGB ↔ HSL with WCAG contrast checker.
JSON Formatter
Pretty-print, validate & minify JSON.
Regex Tester
Live JavaScript regex playground.
URL Encoder
Percent-encode & decode URLs.
Hash Generator
SHA-1/256/384/512 via Web Crypto.
JWT Decoder
Inspect JWT header, payload & claims.
JWT Builder
Sign JWTs with HS256/384/512 in your browser.
CSP Evaluator
Lint Content-Security-Policy for unsafe patterns.
Cron Parser
Explain cron in English + preview next 10 runs.
ID Generator
UUID v4/v7, ULID, NanoID, KSUID — batch generate.
cURL → Code
Convert curl to fetch, axios, Python, Go, PHP.
Timestamp Converter
Unix epoch ↔ human date.
Slug Generator
SEO-friendly URL slugs.
UTM Builder
Campaign URLs for GA4, Plausible, Fathom.