About OpsCheck

Infrastructure checks for sysadmins and hosting teams

OpsCheck is an online portal for practical DNS, SSL, email and network diagnostic checks. It is built for people who need quick, clear technical signals when troubleshooting domains, servers and infrastructure.

Who Maintains OpsCheck

OpsCheck is maintained by Nemanja Jeremić, a Linux system administrator and hosting infrastructure engineer with experience in server security, PHP development, and shared hosting infrastructure. Every tool on OpsCheck is built and tested against real infrastructure to ensure practical, accurate results.

What OpsCheck Provides

OpsCheck provides 25+ browser-based diagnostic tools for:

DNS diagnostics: DNS record lookup, DNSSEC validation, reverse DNS/PTR checks, DNS propagation checking, CNAME and A record analysis.
SSL/TLS checks: SSL certificate inspection, TLS version scanning, certificate chain verification, CRL/OCSP checking, Certificate Transparency log search.
Email authentication: SPF record validation, DKIM key checking, DMARC policy analysis, SMTP server testing, email header analysis.
Network diagnostics: Port scanning, ping testing, HTTP header analysis, redirect chain checking, CORS testing, HTTP version checking.
Server troubleshooting: IP geolocation, blacklist reputation checks, WHOIS domain data, MAC vendor lookup, user agent parsing.
Data utilities: Base64 encoding/decoding, hash generation, JSON formatting, URL encoding, timestamp conversion, subnet calculation.

All core tools run server-side — no client-side JavaScript is required for network diagnostics, ensuring accurate results regardless of local network conditions. Utility tools that do not require network access process data directly in the browser.

Who It Is For

OpsCheck is built for:

System administrators verifying DNS changes, checking SSL expiry, and troubleshooting server configurations.
Hosting engineers diagnosing email delivery problems, SPF/DKIM/DMARC misconfigurations, and DNS propagation issues.
DevOps and SRE teams performing infrastructure checks during deployments, migrations, and incident response.
Web developers testing HTTP headers, redirect chains, CORS configurations, and SSL certificate chains.
IT support staff collecting diagnostic evidence for escalations and confirming user-reported issues.

Technology

OpsCheck is built with Laravel and PHP, running on a dedicated Linux server. DNS queries use native PHP DNS functions against public resolvers. SSL checks use OpenSSL via PHP streams with direct TLS connections. WHOIS data is queried against IANA-registered WHOIS servers over port 43. Vulnerability data comes from the National Vulnerability Database API.

Important Limitations

Diagnostic results depend on public DNS data, network reachability, third-party lookup sources, cache state, rate limits, and the availability of external services. Tools are tested against real infrastructure where possible, but results are not absolute security guarantees. A clean port scan result does not mean a server is secure. A valid SSL certificate does not confirm a site is safe to use.