Fast workflow
Designed to reduce friction with direct upload, quick processing, and one-click export.
Open SSL Certificate Checker, add your file, then choose the target output and run conversion.
This tool is optimized for security utilities and works best with * as inputs.
When processing completes, download the result in * and verify quality before sharing.
SSL Certificate Checker is a privacy-first utility for fast security utilities. It helps you move from * to * with consistent output quality.
Designed to reduce friction with direct upload, quick processing, and one-click export.
Files are handled in an isolated processing flow with minimal retention and clear user controls.
Outputs are tuned for real use cases across *.
A predictable sequence keeps conversion stable across devices and file sizes.
SSL Certificate Checker accepts * and exports *.
The pipeline is designed for privacy-first processing with clear user control over inputs and outputs.
Use high-quality source files, choose the closest matching target format, and avoid repeated reconversion cycles.
SSL Certificate Checker follows a deterministic conversion flow so results are repeatable and easier to troubleshoot when a file behaves unexpectedly.
Fetches TLS certificate details for a hostname.
The server opens a TLS connection to the public hostname you provide. No data is sent beyond the standard TLS handshake. Private/internal network hosts are blocked to prevent SSRF attacks.
Connects to the target host via TLS and retrieves the complete certificate details including subject and issuer DNs, validity period (notBefore/notAfter), Subject Alternative Names (SANs), serial number, signature algorithm, and SHA-256 certificate fingerprint. Supports Server Name Indication (SNI) for hosts behind shared IP addresses. The server blocks private network IPs (RFC 1918) to prevent server-side request forgery (SSRF).
Use this to verify certificate expiry dates before they cause browser warnings, audit SSL/TLS configurations after deploying new certificates, check certificate chains for misconfigurations, verify domain ownership via SANs, or investigate certificate details during security audits.
See the detailed comparison guide or try a related tool: