Decode and view SSL certificate details including subject, issuer, and validity period. Code never leaves your device — formatting and validation run locally in your browser.
Content reviewed October 2026 · About Toolzum
Check SSL/TLS certificate details for any domain via public certificate APIs. View issuer, validity period, days remaining, and SANs. Expiry alerts catch outages before users do — free, no signup.
Encode or decode URLs with percent-encoding. Swaps input/output for quick bidirectional conversion. Code never leaves your device — formatting and validation run locally in your browser.
Decode and inspect SAML assertions and responses for SSO troubleshooting. Code never leaves your device — formatting and validation run locally in your browser.
Translate text to Morse code and decode Morse back — with timing-accurate playback. Learn SOS (···---···) properly — local processing, free, no signup.
Decode binary strings back to readable Unicode text with strict validation. Recover messages from bit dumps — local decoding, free, no signup.
Paste one PEM certificate at a time — chains decode first-certificate-only.
Not-before/not-after dates exactly as encoded. No days-remaining math — compare against today yourself.
Single-certificate view only — paste each chain member separately; truncated sample blobs fail with an honest error.
No — decoding runs locally in your browser, free with no signup.
SSL/TLS Checker
Check a host over HTTPS from your browser — SSL/TLS reachability (which proves the browser validated the certificate chain) plus public issuance history (issuer, expiry, cert count) via crt.sh. No cipher-suite or protocol-version scan: browsers do not expose handshakes.
SSL Checker
Check SSL/TLS certificate details for any domain via public certificate APIs. View issuer, validity period, days remaining, and SANs. Expiry alerts catch outages before users do — free, no signup.