Free tools / SSL certificate checker

Free SSL certificate checker: expiry, issuer and trust

Check a domain's SSL certificate: issuer, validity dates, days left, whether it is trusted, plus the domain registration and expiry dates. Flags what expires soon.

The result appears here as JSON.

One free check per tool and IP address per day. Nothing is stored.

What you get

Certificate subject, issuer, valid-from and valid-to dates, days left and a trusted flag
Domain registration and expiry dates, registrar and nameservers
A warning flag when something expires inside your warning window

Not returned: Registrant or contact details, and private keys (never visible).

Use it from code or an agent

curl "https://api.ambolt.dev/v1/domain-ssl-sweep?domain=www.sitemaps.org&warnDays=30&free=1"

Same tool as an MCP tool (domain_ssl_sweep, free at 30 requests a minute), as a pay-per-call endpoint ($0.005 a call in USDC) and as an Apify Actor. Reference · Docs

Questions

What does days left mean?

The number of days until the certificate the server presents expires.

Does it check the whole chain?

It reports whether the certificate is trusted; the issuer and dates are those of the certificate the server presents.

Can I check many domains?

Use the API or the Apify Actor with a list of domains.