Check certificate expiry, issuer, TLS version & cipher for any domain — free, instant, no signup
⚙ Connecting to server and retrieving certificate...
Get an instant letter grade based on TLS version, cipher strength, and certificate validity — like SSLLabs but via API
See exactly when the certificate expires and days remaining — catch renewals before they lapse
Identify the Certificate Authority (Let's Encrypt, DigiCert, GlobalSign, etc.)
Check which TLS version (1.2, 1.3) and cipher suite the server negotiates
See all domains covered by the certificate — important for multi-domain setups
Track days until expiry across all your domains — integrate into alerting pipelines via JSON API
Measure TLS handshake time in milliseconds — identify slow certificate chains or OCSP stapling issues
Enter any domain name in the checker above. It connects to the server on port 443, retrieves the SSL/TLS certificate, and reports whether it's valid, when it expires, who issued it, and what encryption is used.
When an SSL certificate expires, browsers show security warnings to visitors, which destroys trust and drives away traffic. Search engines may also demote sites with expired certificates. Most certificate authorities offer automated renewal (e.g., Let's Encrypt with certbot).
A Subject Alternative Name (SAN) is an extension to an SSL certificate that allows it to cover multiple domain names. For example, a single certificate might cover example.com, www.example.com, and api.example.com. The SAN list shows all domains a certificate is valid for.
TLS 1.3 is the current recommended version, offering the best security and performance. TLS 1.2 is still acceptable. TLS 1.0 and 1.1 are deprecated and should be disabled. This tool shows which TLS version a server negotiates.
Monitor SSL certificates across your infrastructure programmatically:
curl "https://51-68-119-197.sslip.io/api/ssl?domain=example.com"
import urllib.request, json
url = "https://51-68-119-197.sslip.io/api/ssl?domain=example.com"
data = json.loads(urllib.request.urlopen(url).read())
print(f"Valid: {data['valid']} — Expires: {data['expiry_date']} ({data['days_until_expiry']} days)")
const resp = await fetch('https://51-68-119-197.sslip.io/api/ssl?domain=example.com');
const data = await resp.json();
console.log(`Valid: ${data.valid} — Expires in ${data.days_until_expiry} days`);
if (data.days_until_expiry < 30) console.warn('Certificate expiring soon!');
for domain in example.com api.example.com cdn.example.com; do days=$(curl -s "https://51-68-119-197.sslip.io/api/ssl?domain=$domain" | jq '.days_until_expiry') echo "$domain: $days days" done
Integrate SSL monitoring into alerting pipelines, CI/CD, or dashboards:
Get a Free API Key — 50 requests/day, instant:
RapidAPI PRO/ULTRA — up to 60 req/min, from $9.99/mo: