Free tools
HOSTING &
DOMAIN TOOLS
Fast, free utilities for anyone running a website. Check DNS, SSL, who a site is hosted with, WHOIS, redirects and email blacklists, build the SPF, DKIM and DMARC records your mail needs, then find a better host with the data behind every result. No signup.
34 tools
Popular checks
The Hosting Stack
Trace the DNS, CDN, platform, host, network, registrar and email providers behind any domain in one connected view.
DNS Checker
Look up A, AAAA, MX, TXT, NS, CNAME and SOA records for any domain, plus who runs its nameservers.
Hosting Checker
Find out who hosts any website. We resolve the domain to its provider and link straight to its HostList profile and better-rated alternatives.
SSL Checker
Inspect any site’s SSL certificate: issuer, expiry, covered domains and whether the chain is valid and trusted.
Website Speed Test
Measure any site’s real load performance: Core Web Vitals, a performance score, and where the time goes.
Domain & network
Domain availability search
Check a name across popular extensions and compare published provider prices.
WHOIS Lookup
Look up a domain’s registrar, registration and expiry dates, age, status and nameservers from live registry data.
Domain Expiry Checker
See exactly when a domain expires, how many days are left, and who it is registered with. Live registry data, no signup.
Domain Age Checker
Find out exactly when any domain was first registered, its precise age, expiry date and registrar from live registry data.
DNS Propagation Checker
Query resolvers around the world (Google, Cloudflare, Quad9 and more) to see whether your DNS changes have gone live.
IP Address Lookup
Look up any IP address or domain: location, ISP, network and the hosting provider that owns it.
Reverse IP Lookup
Find other domains hosted on the same IP address, a quick way to spot shared hosting neighbours.
Subnet Calculator
Enter an IPv4 CIDR block to get the network and broadcast address, usable host range, netmask, wildcard and host count.
CMS Detector
Find out what CMS and technology a website runs on: WordPress, Shopify, Wix, and the stack behind it.
Business Name Generator
Generate brandable business names, then screen each for trademark risk and live domain availability before you commit.
Email & deliverability
MX Record Lookup
See the mail servers behind any domain in priority order, with SPF and DMARC checks that decide whether email lands.
Blacklist Checker
Check whether a domain’s IP is listed on major email and spam blacklists that can silently block your mail and traffic.
DMARC Checker
Look up a domain’s DMARC record, read its policy, and see whether it actually protects the domain from spoofing.
SPF Checker
Look up a domain’s SPF record, list the servers it authorises, and catch the errors that break email delivery.
DKIM Checker
Find a domain’s published DKIM keys by probing the common selectors, so you can confirm mail is signed.
Email Header Analyzer
Paste raw email headers to trace the delivery path, timing, and SPF, DKIM and DMARC authentication results.
Email setup & records
Email Migration Checker
Check whether a domain is ready to move email hosts: MX records, the TTL that decides your cutover window, SPF, DKIM and DMARC.
DMARC Record Generator
Build a valid DMARC TXT record: choose the policy, reporting addresses and alignment, then copy the record straight into DNS.
SPF Record Generator
Pick the services that send mail for your domain and get a valid SPF record, with a live count against the ten DNS lookup limit.
DKIM Record Generator
Generate a DKIM key pair in your browser and get the DNS TXT record for your selector, plus the private key for your mail server.
Site diagnostics
Redirect Checker
Trace the full redirect path of any URL, hop by hop, with the status code at each step so you can spot chains and loops.
HTTP Header Checker
Inspect any URL’s response headers and status code, with a security-header audit covering HSTS, CSP and more.
Website Down Checker
Check whether a website is down for everyone or just you, with the live status code and response time.
Password Generator
Generate strong, random passwords in your browser. Nothing is sent anywhere, ever.
Robots.txt Tester
Fetch a site’s robots.txt, read its crawl rules, and test whether any URL is allowed or blocked for Googlebot.
Multiple URL Opener
Paste a list of links and open them all in new tabs at once. Runs entirely in your browser, nothing is uploaded.
XML Sitemap Validator
Fetch a sitemap and check it against the sitemaps.org rules: URL limits, cross-host entries, malformed dates and duplicates.
Uptime Calculator
Turn an uptime percentage into the downtime it actually allows per day, month and year, and check whether an outage breached your SLA.
CSR Generator
Create a certificate signing request and its private key in your browser, ready to hand to any certificate authority.