nginx Config Checker: Find Security and Syntax Mistakes
Static review of an nginx configuration in your browser: syntax slips, old TLS protocols, missing HSTS and redirects, add_header inheritance, PHP-FPM and proxy pitfalls, with suggested fixes by line.
September 30, 2026
CAA and TLSA Checker: Free CAA Record and DANE Test
Reads CAA records (including those inherited from parent domains), compares them with the CA of the live certificate, and checks TLSA records for HTTPS and the MX hosts against DNSSEC and the served certificate.
September 30, 2026
SMTP Test: Free STARTTLS, Certificate and Banner Check
Connects to a mail server on port 587 or 465, reads the greeting, negotiates TLS and shows the certificate, TLS version, AUTH methods and reverse DNS, without sending any message.
September 30, 2026
Domain Health Checker: Free Score for DNS, SSL, Email and Headers
One scan that scores a domain out of 100 across DNS, HTTPS, security headers and email authentication, with a prioritised list of fixes.
September 30, 2026
SIP Ports Firewall Rules: 4 Setups for CSF, firewalld and pfSense
Which ports a PBX really needs (SIP 5060/5061 and the RTP media range), how to open them in CSF, firewalld and pfSense, and how to restrict SIP to your trunk provider so scanners cannot brute-force extensions.
September 30, 2026
DMARC Report Analyzer
Open a DMARC aggregate (RUA) report as received (.xml, .xml.gz or .zip) and see every sending source, message counts, SPF and DKIM alignment and what the receiver did, parsed in your browser.
September 29, 2026
Uptime SSL Blacklist Monitor: Free Email Alerts
Get free e-mail alerts when your website goes down, your SSL certificate is about to expire or your server IP or domain is listed on a major blacklist. Up to five monitors per e-mail address.
September 29, 2026
MTA-STS Checker
Check a domain's MTA-STS setup: the _mta-sts TXT record, the HTTPS policy file, its mode and max_age, whether every MX host is covered, and the TLS-RPT reporting record.
September 29, 2026
DNSSEC Checker
Check whether a domain is signed with DNSSEC: DS records at the registry, DNSKEY records in the zone, matching key tags, algorithms and live validation through Cloudflare and Google.
September 29, 2026
CSR Decoder
Decode a certificate signing request in your browser: see the subject, Subject Alternative Names, key type and size and signature algorithm before you send it to a certificate authority.
September 29, 2026
SSL Certificate Decoder
Decode a PEM SSL/TLS certificate in your browser: subject, issuer, validity dates, SAN names, key, signature algorithm, serial number and SHA-256/SHA-1 fingerprints.
September 29, 2026
Certificate Key Matcher: Free Safe Cert and Key Check
Check whether an SSL certificate, private key and CSR belong together by comparing their public keys in your browser. The private key never leaves your computer.
September 29, 2026