CertObserver vs CertPost

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

CertObserver compared with CertPost
Detail	CertObserver	CertPost
What it does	TLS certificate monitoring and inventory	SSL certificate monitoring that reads the cert your server serves
Stage	Not given	Established
Founded	Not given	Not given
Based in	Not given	GB
Pricing model	Not given	freemium
Pricing	Monthly subscription plans starting at $9/month for the Small plan, with Medium at $29/month, Large at $59/month, and Max at $99/month. All plans include email and Slack alerts.	Not given
Key features	Certificate inventory management Certificate Transparency log monitoring TLS endpoint monitoring Expiration alerts Email and Slack notifications Team collaboration with role-based access Optional alerts for certificate issues	Checks the served certificate, not renewal logs Full certificate chain and intermediate expiry validation Hostname and SAN mismatch detection Any TLS port over IPv4 and IPv6 Domain registration expiry monitoring Certificate Transparency new-issuance alerts Email and webhook alerts Weekly all-clear digest
What makes it different	Monitors Certificate Transparency logs for new certificates on your domains Validates TLS handshakes across multiple protocols	Monitors what your server actually serves, not what renewal logs say Validates every link in the certificate chain, including intermediates Four warnings before expiry instead of one Watches from outside your registrar account No agent installation required
Free plan	Not given	Not given
Open source	Not given	Not given
Platforms	Not given	Not given
Public API	Not given	Not given
Community votes	0	0
DR (Domain Rating by Ahrefs)	50 no change since last check	11 no change since last check
Trust Flow (Majestic)	25	8
Citation Flow (Majestic)	25	28
Referring domains (Majestic)	92	38

3 details filled in for both companies.

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