compare brief · tls / monitoring
sslcheck vs openssl s_client
`openssl s_client` is the raw handshake probe. sslcheck is the same first look turned into a readable CLI with SANs, expiry, chain depth, key strength, JSON output, and severity exit codes for CI and cron.
openssl s_client alternative
cron-friendly
ci exit codes
no signup
use sslcheck when
- You want a fast expiry check without decoding PEM blobs.
- You need SANs, key strength, and chain depth in one readable pass.
- You want CI or cron to fail on critical TLS issues.
- You are checking several hosts in one command.
- You prefer JSON output over shell archaeology.
use openssl s_client when
- You need raw handshake debugging or vendor-doc parity.
- You want to inspect the certificate chain by hand.
- You are already deep in a network incident and want the raw transcript.
- You do not mind post-processing the output yourself.
Feature comparison
| Feature | sslcheck | openssl s_client |
|---|---|---|
| Human-readable summary | ✓ yes | – raw transcript |
| Expiry countdown | ✓ yes + severity badge | – manual |
| SAN extraction | ✓ full list | – manual decode |
| Key algorithm + size | ✓ RSA/ECDSA + bits | – manual |
| Certificate chain depth | ✓ yes | – manual |
| Severity exit codes | ✓ 0 / 1 | – no |
| JSON output | ✓ yes | – no |
| Multi-target runs | ✓ yes | – manual loop |
| Zero-dependency npm install | ✓ yes | – bundled with OS |
FAQ
Is sslcheck an alternative to openssl s_client?
Yes. sslcheck is a free TLS certificate inspector that keeps the useful parts of
openssl s_client and removes the PEM noise. It reports issuer, SANs, expiry, key strength, and chain depth in a form that works in terminals, CI jobs, and cron monitors.What does sslcheck add that openssl s_client does not?
sslcheck adds a human-readable summary, JSON output, severity-aware exit codes, and multi-target runs. That makes it easier to plug into dashboards, GitHub Actions, and daily expiry checks.
Do I still need openssl s_client?
Sometimes. If you need raw transcript-level debugging, use the classic tool. If you only need to know whether the cert is healthy, expiring, or missing SAN coverage, sslcheck is faster to read and automate.
Is sslcheck free?
Yes. The CLI is MIT-licensed and published on npm. The web page has no account requirement and no normal-use paywall.