H1 · Infrastructure, Bots & DNS

    TLS Certificate Checker — is your SSL valid and not expiring soon?

    An expired TLS certificate doesn't just remove the padlock — browsers block the whole site with a full-page security warning. This check looks at whether your certificate is valid, trusted, matches your domain, and isn't about to expire. Because certificates have a fixed lifespan and must be renewed, an unnoticed expiry can take your site offline for every visitor at once.
    Updated June 2026 · Technical SEO & GEO · Part of Infrastructure, Bots & DNS

    Check your TLS certificate

    Paste a URL — GEObubbly checks whether your TLS certificate is valid, trusted and not close to expiring.

    ✓ Free check✓ 1 signal✓ No signup required
    In short: Your TLS certificate must be valid, trusted, match the domain and have comfortable time before expiry. An expired certificate doesn't just remove the padlock — browsers block the entire site with a full-page warning.

    What does the TLS certificate check verify?

    It checks the health of your site's TLS/SSL certificate beyond just having HTTPS. Specifically:

    • Validity — the certificate is currently valid and issued by a trusted authority.
    • Domain match — it's issued for the domain being served (not a mismatched or wildcard gap).
    • Expiry window — how soon it expires, flagging certificates close to their end date so they can be renewed in time.

    A valid certificate with comfortable time before expiry passes; one nearing expiry is a warning; an expired, untrusted or mismatched certificate is a fail.

    How is it evaluated, and how is it scored?

    GEObubbly inspects the certificate served on the live TLS connection, checking its validity, trust chain and expiry date. It's a core, scored Infrastructure check that runs server-side against the live connection.

    Criteria: Pass — valid, >30 days to expiry. Warning — valid but <30 days, or chain issues. Fail — expired, self-signed, mismatched or untrusted.

    Why TLS certificate health matters for SEO and GEO

    This check goes a step beyond having HTTPS to the ongoing health of the certificate that makes HTTPS work. TLS certificates are issued for a fixed period and must be renewed before they expire — and an expired certificate is far worse than no padlock: modern browsers show a full-page security interstitial warning users the connection isn't private, which most people will not click past. In effect, an expired certificate takes your entire site offline for every visitor, and crawlers hitting the error will struggle to access your content too. The same hard failure happens if the certificate is untrusted (self-signed or from an unrecognised authority) or doesn't match the domain. These outages are usually self-inflicted and avoidable: certificates from providers like Let's Encrypt are typically auto-renewed, but renewal can silently break, so monitoring the expiry date is essential. For both SEO and GEO, availability is the prerequisite for everything — a site behind a certificate error can't be crawled, ranked or cited. Keeping the certificate valid and comfortably ahead of expiry protects uptime.

    How this check scores
    Pass: Valid certificate with >30 days before expiry, trusted chain, matching domain.
    Warning: Valid but <30 days to expiry or minor chain issues.
    Fail: Expired, self-signed, mismatched or untrusted certificate.

    FAQ

    When a TLS certificate expires, browsers stop trusting the connection and display a full-page security warning — an interstitial telling the user the connection isn't private and advising them not to proceed. Unlike a missing padlock, this blocks access to the whole site: most visitors won't (and shouldn't) click past the warning, so the site is effectively offline for everyone. Crawlers hitting the certificate error also struggle to access your content. Because certificates have fixed lifespans, an expiry that isn't caught in time causes a sudden, total outage, which is why monitoring renewal is critical.

    Related checks in Infrastructure, Bots & DNS

    H4
    DNS resolution & redundancy

    Audit your page across all 9 checks in Infrastructure, Bots & DNS

    See which checks pass, warn or fail — in seconds.

    Run a free audit →
    ← Back to the full Infrastructure, Bots & DNS guide
    Free TrialContact