Certificate Expiry Checker (Paste PEM)
Paste one or more PEM certificates and instantly see the days remaining on each, with expired / expiring-soon warnings — audit a folder of certs without openssl or uploading anything.
About Certificate Expiry Checker (Paste PEM)
Certificate Expiry Checker takes one or many pasted PEM certificates and shows the days remaining on each, with expired and renew-soon warnings — audit a whole folder of certs in one paste, fully offline.
How to use Certificate Expiry Checker (Paste PEM)
- 1Paste or type your input into the box above — a sample is pre-filled so you can try it instantly.
- 2Set any options on offer (mode, key, format) to match what you need.
- 3The result appears the moment you type — no button to press, no waiting.
- 4Click Copy to grab the output — Certificate Expiry Checker (Paste PEM) keeps everything on your device.
Why use Certificate Expiry Checker (Paste PEM)?
- ✓Auditing /etc/ssl or a secrets repo for certificates about to lapse
- ✓Checking internal CA and client certificates that public monitors can't see
- ✓Confirming a renewal actually replaced the old certificate everywhere
- ✓100% free with no sign-up, no watermark and no usage limits
- ✓Runs entirely in your browser — your text and keys are never uploaded, stored or logged
- ✓Works offline once loaded, with instant results and one-click copy
Frequently asked questions
How long are SSL certificates valid?+
Publicly-trusted TLS certificates are capped at 398 days, and the CA/Browser Forum has voted to shorten lifetimes in stages over the coming years — so renewal automation (ACME/Let's Encrypt) is becoming mandatory rather than convenient. Internal CA certs can be longer, which is exactly why they get forgotten and need auditing.
Can this check a live website's certificate?+
This tool inspects PEM files you paste, entirely offline — ideal for internal certs that public checkers cannot reach. To query a live hostname instead, use our SSL Certificate & HTTPS Checker.
Is it free to use?+
Yes — completely free with no sign-up, no account and no usage limits. There is no paywall, so you can encode, decode and convert as much as you like.
Is my data private and secure?+
Yes. This tool runs entirely in your browser using client-side JavaScript — your input is never uploaded to a server, stored or logged. Once the page has loaded you can use it offline, which makes it safe for tokens, keys and confidential data.
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