SSL Certificate Checker 🔒

Check SSL/TLS certificates for any list of domains — expiry date, days until expiry, issuer, Subject Alternative Names (SAN), serial number, TLS version and cipher. No proxy, no browser, no login. Runs on Apify's free datacenter and works from anywhere.

Perfect for certificate expiry monitoring, security audits, DevOps automation and uptime / SSL health checks. Feed it a list of hostnames and get one clean JSON row per host.

👉 Run SSL Certificate Checker on Apify »

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✨ What it does

For every host you give it, the actor performs a real TLS handshake using Python's standard-library ssl + socket (the exact same code path a browser or curl uses), reads the server certificate and reports:

Field	Description
host	Hostname that was checked
port	Port used (default 443)
valid	true if the certificate chain verified (trusted, in-date, hostname matches)
common_name	Subject Common Name (CN)
issuer_org	Issuing Certificate Authority organization (e.g. Sectigo Limited, Google Trust Services, DigiCert Inc)
issuer_cn	Issuer Common Name
valid_from	notBefore date (ISO-8601 UTC)
valid_to	notAfter / expiry date (ISO-8601 UTC)
days_until_expiry	Days left before the certificate expires (negative if already expired)
is_expired	true if the certificate is past its expiry date
san	Array of DNS Subject Alternative Names
serial_number	Certificate serial number
tls_version	Negotiated protocol (e.g. TLSv1.3)
cipher	Negotiated cipher suite
error	Verification/handshake error message, if any
scraped_at	ISO-8601 timestamp of the check

Even for expired or self-signed certificates the actor still reports full details (issuer, expiry, SAN…) — it does a second, verification-disabled handshake so you always see why a certificate failed, with is_expired set correctly.

📥 Input

{
  "hosts": ["github.com", "expired.badssl.com", "google.com"],
  "maxItems": 100
}

Property	Type	Description
hosts	array (required)	Hostnames or URLs. Scheme and path are stripped automatically. Add :port for non-standard ports.
maxItems	integer	Cap on hosts checked per run. Default 100, max 1000.

You can paste bare domains (example.com), full URLs (https://example.com/login) or host:port (mail.example.com:8443).

📤 Output

One dataset item per host:

{
  "host": "github.com",
  "port": 443,
  "valid": true,
  "common_name": "github.com",
  "issuer_org": "Sectigo Limited",
  "issuer_cn": "Sectigo Public Server Authentication CA DV E36",
  "valid_from": "2026-06-03T00:00:00+00:00",
  "valid_to": "2026-09-30T23:59:59+00:00",
  "days_until_expiry": 89,
  "is_expired": false,
  "san": ["github.com", "www.github.com"],
  "serial_number": "0AF1E2D3C4B5A6...",
  "tls_version": "TLSv1.3",
  "cipher": "TLS_AES_128_GCM_SHA256",
  "error": null,
  "scraped_at": "2026-07-03T12:00:00+00:00"
}

Export as JSON, CSV, Excel, HTML or RSS from the dataset, or pull it via the Apify API.

💡 Use cases

• Certificate expiry monitoring — schedule a daily run over your domains and alert when days_until_expiry drops below your threshold. Never get surprised by an expired cert again.
• Security & compliance audits — verify issuers, minimum TLS version and cipher suites across an estate.
• DevOps / SRE automation — wire the JSON into CI, dashboards, Slack or PagerDuty.
• Uptime & SSL health checks — combine valid, is_expired and error for a one-glance health signal.
• Pre-migration checks — confirm SAN coverage before switching DNS or CDNs.

💰 Pricing

Pay-as-you-go, roughly $1 per 1,000 hosts checked (input) plus the JSON output — thanks to lightweight stdlib TLS handshakes with no proxy or browser overhead, most runs cost a few cents. Free Apify plan is enough to get started.

⚖️ Why this actor

	SSL Certificate Checker	Manual openssl s_client	Browser padlock
Bulk / many domains	✅ Yes	❌ One at a time	❌
Structured JSON/CSV	✅	❌ Raw text	❌
Days-until-expiry	✅ Computed	❌ Manual math	❌
Reads expired/self-signed	✅	⚠️ Flags/quirky	⚠️
Schedulable + API	✅	❌	❌
No proxy needed	✅	✅	—

🔗 Related actors by ninhothedev

• Security Headers Checker
• DNS Records Scraper
• RDAP Domain Scraper
• Website Tech Stack Detector

🛟 Support

Questions, feature requests or a domain that behaves oddly? Open an issue on the actor's Issues tab and I'll take a look.

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Keywords: SSL checker, TLS certificate checker, certificate expiry monitor, SSL expiry, days until expiry, certificate issuer lookup, SAN checker, subjectAltName, TLS version, cipher, HTTPS monitoring, SSL audit, DevOps SSL, cert monitoring, security headers, domain SSL.