DomainApp

Free Domain Tools

DomainApp is a free suite of domain tools. Check WHOIS records, look up DNS, verify SSL certificates, inspect HTTP headers, find expired domains, and discover available domain names.

WHOIS Lookup

See domain registration details including registrar, creation date, expiry, domain age, and nameservers.

DNS Lookup

View A, AAAA, MX, NS, TXT, CNAME, and SOA records for any domain.

SSL Certificate Check

Verify SSL/TLS certificates — issuer, validity dates, days remaining, and subject alternative names.

HTTP Header Check

Inspect server response headers including security headers, caching, and redirects.

Redirect Checker

Follow the full redirect chain from HTTP to final destination. See each hop with status codes.

MX Validator

Check mail server records and verify they are reachable on SMTP ports.

Blacklist Check

Check if a domain's IP is listed on major spam blacklists (Spamhaus, Spamcop, Barracuda, SORBS, and more).

Technology Detector

Detect the CMS, JavaScript framework, CSS framework, CDN, analytics, and hosting platform used by any website.

Sitemap & File Finder

Check for robots.txt, sitemap.xml, ads.txt, security.txt, and other common files.

Social Media Username Check

Check if a username is available on GitHub, Twitter/X, Instagram, TikTok, Reddit, YouTube, and more.

Page Speed Test

Measure DNS resolution, TCP connect, and total page load time with color-coded results.

Domain Age Calculator

See exactly how old a domain is — creation date, age in years/months, and total days since registration.

Hosting Provider Lookup

Identify who hosts a domain — IP address, organization, ASN, reverse DNS, and detected provider name.

Find Expired Domains

Discover available domain names with pronounceable, memorable patterns. Filter by .com, .net, .org and more.

Domain Name Suggestions

Generate domain ideas from keywords with common prefixes and suffixes across multiple TLDs.