WQI.web​qualityindex
Method v1.2.0 86 live / 86 total factors methodology

methodology / Security & Infrastructure / #5

SSL certificate validity & expiration window

#5 · Required · Web Standards · security · Security & Infrastructure · weight 2% · impl implemented · method v1.2.0

Web Standards item — Security

This factor is part of Web Standards — the table-stakes binary layer of the score. It is graded pass/fail and gates the Web Quality score; it is not weighted into Web Quality itself.

Pass criteria
Tolerant — passes on pass or warn.
Web Standards label
Valid TLS certificate
Why it's required
Every modern browser will block or warn on an invalid certificate. An expired or self-signed cert breaks the site for ordinary visitors.
Same factor, two depths.

What we measure

Your SSL certificate proves to visitors that they're connecting securely. Expired or missing certificates trigger 'Not Secure' warnings.

How to improve your score

Use Let's Encrypt (free, auto-renewing) or your hosting provider's managed SSL. Configure auto-renewal so it never expires.

Facts

Ticket
WEBQ-5
Category
Security & Infrastructure
Status
live
Weight
2%
Data source
Service cost
crt.sh queries (free) + TLS handshake parsing
Scoring impl
implemented
Method version
v1.2.0

Scoring

Scoring formulas are versioned with the methodology. The current method (v1.2.0) maps raw measurements to pass, warn, fail. Factor weights determine how much each contributes to the composite — see the methodology index for the full table.

Cited by these standards

Standards in the Standards Library whose satisfiedBy requirement tree references this factor. Each link goes to the standard's full entry — methodology, scope, and the other factors it relies on.

Version history

Version Change Date
v1.2.0 Factor introduced. Status: live. Scoring impl: implemented. 2026-04-25

← back to methodology