Certificate Key Matcher

Verify that an SSL/TLS certificate and private key belong together. Everything runs in your browser.

1 Certificate

2 Private Key

3 Match

Certificate

Drop certificate file or click to browse

.CRT .CER .PEM

or paste

Private Key

Drop key file or click to browse

.KEY .PEM

or paste

Your certificate and key never leave your browser. All matching runs locally via JavaScript — no data is transmitted to any server.

Provide Both

Paste or upload your certificate and private key

Extract

Public key modulus is extracted from each

Compare

SHA-256 fingerprints are compared to verify the match

Use this tool when installing an SSL certificate on a server and you need to verify that the certificate and private key were generated together.

A mismatched pair will cause TLS handshake failures and prevent your site from loading over HTTPS.

Zero network transmission — your certificate and private key are never sent to any server
100% browser-based — matching runs entirely in JavaScript on your device
No cookies, no tracking, no storage — nothing is logged or persisted
Works offline — once loaded, the tool functions without an internet connection

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Stop sophisticated Phishing, BEC, Malware, and Zero-Day threats before they reach your users!