All tools

27 checkers and 12 record generators. Every checker links to the generator that fixes what it finds.

DNS

5 tools

DNS LookupQuery any DNS record type for a domain and compare authoritative and resolver answers.DNS Health CheckerAudit a domain's DNS configuration for missing records, delegation problems and common misconfigurations.DNS Propagation CheckerSee what a range of public resolvers return for a record and understand any lag between them.DNSSEC CheckerValidate the DNSSEC chain of trust from the root to your zone and explain any broken link.CAA Record CheckerCheck which certificate authorities are allowed to issue for your domain and spot missing or conflicting records.

Email

9 tools

MX LookupList the mail servers for a domain, confirm they respond, and check whether they offer STARTTLS.SPF CheckerValidate your SPF record, visualize the include tree and count DNS lookups against the 10-lookup limit.DKIM CheckerFind and validate DKIM public keys by trying common selectors or the one you provide.DMARC CheckerRead your DMARC record, explain every tag, and say what the published policy does and does not ask receivers to do.BIMI CheckerCheck your BIMI record and logo, and whether your DMARC policy meets the prerequisites.MTA-STS CheckerValidate your MTA-STS DNS record and policy file so inbound mail cannot be downgraded to plain text.TLS-RPT CheckerCheck whether your domain publishes a TLS-RPT record so you receive reports about failed secure mail delivery.SMTP TLS CheckerConnect to a mail server and check STARTTLS support, certificate validity and the negotiated protocol.Email Header AnalyzerPaste raw email headers to see the delivery path, hop delays, authentication results and phishing red flags.

Security

3 tools

SSL CheckerInspect the TLS certificate chain, expiry, protocols and cipher suites of any host and get a grade.Security Headers CheckerCheck HSTS, CSP, X-Frame-Options and cookie flags, with copy-paste fixes for common servers.Port CheckerCheck which of 21 common TCP ports answer on a host you run, and what each open one exposes.

Web

6 tools

HTTP Header CheckerView the full request and response headers for any URL, including caching, compression and server details.Redirect CheckerFollow every redirect hop with status codes, timing and headers, and spot loops and chains.Domain Health CheckRun every DNS, email, TLS and web security check in one go and get a single grade with a plain-language fix list.Website Speed TestSee what real Chrome visitors experience, and which bytes on one page load are worth removing.SEO CheckerCheck one page's indexability, canonical, metadata, headings, structured data, robots.txt and sitemap.Technology LookupIdentify the CMS, framework, server, CDN and analytics a site discloses, with the evidence for each.

Network

2 tools

Blacklist CheckCheck an IP address or a domain's mail servers against the public DNS blacklists we are licensed to query.Reverse DNS LookupResolve an IP address to its PTR hostname and verify forward-confirmed reverse DNS for mail servers.

Domain

2 tools

WHOIS LookupLook up registration data via RDAP: registrar, creation and expiry dates, nameservers and EPP status codes explained.Domain Age CheckerFind out when a domain was first registered and how long until it expires.

Generators

12 tools

SPF Record GeneratorAnswer a few questions about who sends your mail and get a valid SPF record with provider-specific instructions.DMARC Record GeneratorBuild a DMARC record step by step, from monitoring to full enforcement, with reporting addresses included.DKIM Record GeneratorTurn a DKIM public key and selector into a correctly formatted DNS TXT record.MX Record GeneratorGenerate correctly prioritized MX records for a mail provider, ready to paste into your DNS host.CAA Record GeneratorBuild a correct CAA record naming the certificate authorities allowed to issue TLS certificates for your domain.TXT Record GeneratorBuild a correctly formatted and escaped DNS TXT record for verification, SPF or any custom value.MTA-STS GeneratorGenerate the MTA-STS DNS record and the HTTPS-hosted policy file it depends on, together.TLS-RPT Record GeneratorGenerate a valid TLS-RPT DNS record so senders report on TLS delivery failures to your mail servers.BIMI Record GeneratorGenerate a valid BIMI DNS record pointing to your SVG logo and optional Verified Mark Certificate.Security Headers GeneratorAnswer a few questions about your site and get security header config snippets for common web servers.SSL Config GeneratorGenerate a modern TLS protocol and cipher suite configuration for your web server, based on your compatibility needs.security.txt GeneratorGenerate a valid security.txt file with your vulnerability disclosure contact, policy link and expiry date.