Defaults.Exposed › September 2026 census › v10 registry › Certificate valid
Certificate valid
Methodology v10 · canonical ID cert-valid · TLS & Certificates · scored · census as of September 5, 2026
A trusted, correctly-issued certificate; an invalid one throws scary browser warnings.
Definition
| Canonical ID | cert-valid |
|---|---|
| Category | TLS & Certificates |
| Grade impact | Scored, counts toward the grade |
| Pass | The presented certificate chain validates to a trusted root, matches the hostname, and is within its validity period. |
| Fail | The certificate is self-signed, expired, name-mismatched, or otherwise fails validation. |
| Example (passing) | CN=example.com, issued by a publicly trusted CA, chain validates |
No-data rule: when this check couldn't be determined for a domain (timeout, SERVFAIL, redacted source) it returns N/A and is excluded from that domain's scoring denominator: "couldn't determine" is never counted as a failure. "Determined absent" is a real fail.
Prevalence across the census
89.1% of HTTPS-serving domains present a valid, trusted certificate (189,117,751 of 212,154,494, as of September 5, 2026).
Census denominator: 316,600,902 graded domains; this check is measured only against HTTPS-serving domains (212,154,494). Aggregates only: never an individual domain's result.
Fix it
Plain-English impact, cost of ignoring it, and step-by-step remediation: defaults.exposed/fix/certificate
Cite this check
Defaults.Exposed, "Certificate valid (cert-valid)", Grading Methodology v10 (census as of September 5, 2026). https://defaults.exposed/v10/methodology/cert-valid
Permalink: https://defaults.exposed/v10/methodology/cert-valid ·
All 34 checks: v10 registry ·
Machine-readable: /v10/methodology/checks.json ·
Licence: open data