All Tools
Every tool on this site, grouped by category.
Web Validators
HTML Validator
Check HTML for spec errors, accessibility problems, and SEO markup issues.
Open tool →CSS Validator
Find invalid properties, malformed selectors, and unknown values in CSS.
Open tool →JSON Validator
Validate, format, and minify JSON with precise error locations.
Open tool →XML Validator
Check XML for well-formedness issues like unclosed or mismatched tags.
Open tool →Image Metadata Validator
Check an image's EXIF, IPTC, and XMP metadata against the IPTC Photo Metadata Standard, including rights and Google Images support.
Open tool →HTTP & Crawling
HTTP Status Checker
Check HTTP status codes, redirect chains, and server responses for multiple URLs.
Open tool →Response Stability Test
Run up to 20 sequential requests to check HTTP status, latency and response consistency.
Open tool →Redirect Matrix
Test http/https and www/non-www host variants, follow every redirect hop, and compare destinations across browser and crawler User-Agents.
Open tool →HTTP Methods
Compare GET, HEAD, and OPTIONS responses for the same URL to spot method-specific status, redirect, and header mismatches.
Open tool →Cache Behavior
Send a small controlled sequence of repeated requests to observe cache status transitions, ETag stability, and Cache-Control consistency.
Open tool →Conditional Requests
Test If-None-Match and If-Modified-Since against a URL's own ETag and Last-Modified headers to verify 304 Not Modified support.
Open tool →Security Headers
Semantic analysis of CSP, HSTS, and other security headers, including GET vs HEAD parity and redirect-chain behavior -- not just presence checks.
Open tool →Content Negotiation
Test HTTP content negotiation by sending different Accept headers (HTML, Markdown, JSON, XHTML, */*) and comparing the responses.
Open tool →Compression & Encoding
Compare identity, gzip, Brotli, and Zstandard representations of a URL to measure real compression ratios and detect malformed encoded responses.
Open tool →SEO Tests
AI & Crawlers
Accessibility
Domain Security
Domain Security Score
One weighted 0-100 score combining malware/phishing reputation, spam/abuse, infrastructure, transport security, DNS security, registration, popularity, and authority signals.
Open tool →HSTS Preload
Whether the domain is on the browser HSTS preload list.
Open tool →Cloudflare Radar Domain Ranking
Cloudflare Radar's domain categorization, read for malicious-category flags.
Open tool →VirusTotal
Aggregated malware/phishing verdicts from dozens of security vendors.
Open tool →Google Web Risk
Google Cloud's Web Risk Lookup API, checked for malware, social engineering, and unwanted software matches.
Open tool →Spamhaus
Spamhaus Domain Block List (DBL) lookup for spam/malware-associated domains.
Open tool →URLhaus
abuse.ch's database of malware-distribution URLs hosted on this domain.
Open tool →AbuseIPDB
Abuse reports against the domain's hosting IP address.
Open tool →DNSBL / RBL
General-purpose DNS-based real-time blocklist lookup against the domain's IP.
Open tool →SURBL
SURBL multi-list domain reputation lookup.
Open tool →URIBL
URIBL multi-list domain reputation lookup.
Open tool →PhishTank
Community-verified phishing URL database.
Open tool →TLD Spam / Abuse Ranking
Aggregate spam/abuse rate for the domain's top-level domain.
Open tool →ICANN Domain Metrica
ICANN's aggregated abuse-feed and popularity data for this domain.
Open tool →Spamhaus Intelligence API
Spamhaus's proprietary reputation score, blocklist listing status, and threat tags via their Intelligence API.
Open tool →DNSSEC
Whether DNS responses for this domain are cryptographically signed and validated.
Open tool →CAA
Which Certificate Authorities are authorized to issue certificates for this domain.
Open tool →SPF
Which mail servers are authorized to send mail as this domain.
Open tool →DKIM
Cryptographic signing keys for outbound mail, checked against common selectors.
Open tool →DMARC
Policy telling mail receivers what to do with mail that fails SPF/DKIM.
Open tool →MTA-STS
Whether inbound mail transport is required to use authenticated TLS.
Open tool →TLS-RPT
Whether failed TLS mail delivery attempts are reported.
Open tool →SSL/TLS
Certificate validity, expiry, and negotiated TLS protocol version.
Open tool →Advanced TLS Checker
SEOTechTests' own advanced TLS/SSL configuration assessment -- certificate, protocols, cryptography, and configuration findings.
Open tool →Certificate Transparency
Public CT log history for certificates issued to this domain.
Open tool →CSP
Content-Security-Policy presence and directive analysis.
Open tool →Mixed Content
Hard-coded http:// resource references on an HTTPS page.
Open tool →security.txt
RFC 9116 security.txt vulnerability-disclosure contact file.
Open tool →Domain Age
How long ago this domain was registered, via RDAP.
Open tool →RDAP / Registrar
Registrar and registration data via the RDAP protocol.
Open tool →Domain Registration Status
EPP status codes revealing holds, pending deletion, or transfer locks.
Open tool →Nameservers
Configured nameservers and basic redundancy check.
Open tool →Hosting ASN
Which network (Autonomous System) hosts this domain.
Open tool →IP Reputation
Abuse history of the domain's hosting IP address.
Open tool →Tranco Rank
Independent, research-grade domain popularity ranking.
Open tool →Cloudflare Radar Rank
Cloudflare's own traffic-based domain popularity rank.
Open tool →