The problem

Developers and ops teams get blindsided by expired SSL certificates because checking expiry requires remembering a multi-flag openssl s_client command and parsing its dense output — so certs get forgotten until the site goes red.

If you've hit this before, you know how it goes — you Google the openssl command, squint at wall-of-text output, and compute the expiry date by hand. Or you just forget until monitoring fires.

As a solution, I created cert-peek

Check SSL certificate expiry and details for any domain in seconds from your terminal

It's zero-dependency Node.js, so you can run it immediately without installing anything:

npx cert-peek github.com

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Output:

$ npx cert-peek github.com Domain: github.com Issuer: DigiCert Inc Valid from: 2025-03-12 Expires: 2026-03-12 Status: OK -- 303 days remaining

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Check multiple domains at once:

npx cert-peek google.com stripe.com myproductionsite.com

Enter…