Certificate & TLS inspector

CertGUARD

Free100% offlineWindows · .NET 10

CertGUARD is a free, defensive inspector for X.509 certificates and TLS configuration. Analyse a local certificate file fully offline, or check the certificate presented by one of your own TLS endpoints — with content, validity, chain and risk signals.

Download

ApplicationWindows installer (.exe) Source codeFull project (.zip) User guide (FR)HTML User guide (EN)HTML

Free download. No account, no telemetry — the tool runs entirely on your machine.

What it does

Reads PEM, DER, CRT, CER, PFX / P12 (password supported)
TLS endpoint check: certificate + protocol + cipher suite
Read-only Windows certificate store browser (certmgr / certlm)
Full details: subject, issuer, validity, SAN, usages, key, thumbprints
Certification chain and colour-coded validity status
Risk analysis: expiry, weak key, SHA-1, self-signed, excessive lifetime
PEM export of the certificate
100% offline for files, FR / EN, self-contained app

Screenshots

CertGUARD — Inspect a certificate file (offline) — Inspect a certificate file (offline)

CertGUARD — Check one of your TLS endpoints — Check one of your TLS endpoints

CertGUARD — Read-only Windows certificate store — Read-only Windows certificate store

CertGUARD — About & feature list — About & feature list

Need the paid GUARD audit tools?

EntraGUARD and AdGUARD run 494 read-only security controls.

See the audit tools →