SSL certificate checker
Check a site’s SSL certificate the way a browser meets it: whether it is valid for the name, who issued it, the days left, the chain as sent, the TLS version, old versions still let in, and whether http:// moves to https:// with HSTS.
- Day 0 to 60Issued, and in use
- Day 60 to 90Renewed here, before it expires
example.comIts own certificate, sent by the serverIntermediateSent by the server with itRootAlready trusted, kept by the browser
Renewal runs on its own with a month to spare, and the server sends the intermediate, so a crawler that never fetches one still trusts the chain.
What does it check?
No rule in the rulebook covers this, so here is what it reads.
- Whether the certificate is valid for the name, and who issued it
- When it expires, and how many days are left
- Whether the chain is whole, so every browser and crawler trusts it
- The TLS version the server offers
Questions
What happens when a certificate expires?
Browsers show a warning in place of the page, and crawlers stop reading it.
Does https help a site rank?
Google counts it as a small signal. A site without it is marked not secure in every browser.
Why does my certificate work in one browser but not another?
Usually an intermediate certificate is missing from the chain. Some browsers fetch it themselves, and many crawlers do not.
The whole site
One page is one part. A read checks every page against the whole rulebook and says what to fix first.
Read a whole site