SSL Certificate Checker - HTTPS Expiry Monitor

Check SSL/TLS certificates for domains and collect the expiry date, issuer, subject, DNS names, match status and days until expiry in a structured dataset. Use it for website monitoring, client audits, uptime workflows, SEO checks and security operations.

What is the SSL Certificate Checker?

An expired or misconfigured SSL certificate can break a website, damage trust, interrupt checkout flows, hurt SEO signals and create urgent support incidents. This actor checks certificates directly over TLS and returns the important fields in a clean Apify dataset.

Paste domains or HTTPS URLs and the actor connects to each host on port 443 by default. It validates the certificate using Python's trusted CA bundle, reads the certificate metadata and calculates the number of days until expiry. The output can be exported to JSON, CSV or Excel, scheduled in Apify, or sent to a webhook for alerts.

Common use cases

Use this actor to monitor your own domains, audit client websites, check landing pages before campaigns, verify SSL status during migrations, watch certificates after DNS changes, build a weekly compliance report, or feed certificate expiry data into Slack, email, Make, Zapier or n8n.

Agencies can run it across client portfolios. DevOps teams can use it as a lightweight external check. SEO teams can catch HTTPS problems before crawlers and users notice. Marketplace sellers can verify many storefront domains at once.

Input

Provide one or more domains or HTTPS URLs.

{
  "domains": [
    "apify.com",
    "https://example.com"
  ],
  "port": 443
}

Output

Each dataset item represents one checked host.

{
  "domain": "apify.com",
  "port": 443,
  "subject": {
    "commonName": "apify.com"
  },
  "issuer": {
    "organizationName": "Google Trust Services"
  },
  "serial_number": "1234567890",
  "version": 3,
  "not_before": "2026-06-01T00:00:00+00:00",
  "not_after": "2026-08-30T23:59:59+00:00",
  "days_until_expiry": 54,
  "is_expired": false,
  "dns_names": ["apify.com", "*.apify.com"],
  "matches_domain": true,
  "error": null
}

Output fields

• domain - normalized host checked by the actor.
• port - TLS port used.
• subject - certificate subject fields.
• issuer - certificate issuer fields.
• serial_number and version - certificate identifiers.
• not_before and not_after - validity window in ISO format.
• days_until_expiry - full days remaining.
• is_expired - true when the certificate is already expired.
• dns_names - Subject Alternative Name DNS entries.
• matches_domain - whether the certificate covers the checked domain.
• error - connection or validation error, if any.

Why use this actor?

Certificate monitoring is simple until it is forgotten. Apify scheduling makes it easy to run this check daily or weekly and alert before a certificate expires. Because the actor connects directly over TLS and does not use a browser, runs are quick and cheap.

Example workflows

For website operations, schedule the actor daily across your production domains and alert when days_until_expiry drops below 30, 14 or 7 days. For agencies, run it across client domains before monthly reporting and identify hosts that need renewal. For migrations, check certificates before and after DNS changes to confirm the correct hostname is covered.

For SEO and conversion teams, HTTPS problems are not just technical noise. A certificate error can stop visitors from reaching a landing page, interrupt checkout, or reduce trust at exactly the wrong moment. This actor gives non-engineering teams a simple dataset they can understand and act on.

Integration ideas

Send results to Make, Zapier, n8n or a webhook after each scheduled run. Filter for is_expired = true, matches_domain = false, or days_until_expiry below your threshold. Store results in Airtable, Google Sheets or a database to keep a historical record of certificate health across a portfolio.

You can combine this actor with sitemap or domain discovery tools. First collect domains from websites, CRMs, landing page lists or client inventories, then check SSL status for each domain. The actor returns one row per domain, which makes it easy to join with existing business records.

Notes and limits

The actor checks the certificate as seen from the Apify runtime. It uses standard TLS validation. If a server blocks outbound connections, requires unusual SNI behavior, or serves different certificates by region, results may vary. For private intranet hosts, run from an environment that can reach those hosts.

Best practices

Monitor important domains before the renewal window becomes urgent. Include both apex domains and key subdomains because they may be served by different certificates or infrastructure. Review matches_domain as well as the expiry date; a valid certificate is still a problem if it does not cover the hostname users visit. If a check fails, inspect the error field and retry before escalating, since temporary DNS or network issues can happen.

For larger portfolios, keep a simple owner field in your own spreadsheet or database and join it with this output so every expiring certificate has a responsible team attached.

FAQ

Can it monitor certificate expiry?

Yes. Schedule the actor and alert when days_until_expiry drops below your threshold.

Does it validate the certificate chain?

It uses Python's standard SSL context, which validates against trusted certificate authorities.

Can I check non-standard ports?

Yes. Set the port input to the TLS port you want to inspect.

Does it crawl websites?

No. It opens a TLS connection only and reads certificate metadata.

You might also like

• URL Shortener Expander - inspect redirect chains.
• Robots Sitemap Analyzer - audit crawl rules.
• Sitemap URL Extractor - collect URLs from XML sitemaps.

Keywords

SSL checker, TLS certificate checker, HTTPS expiry monitor, certificate expiry API, SSL monitoring, website security audit, domain certificate checker, SEO HTTPS check, Apify SSL checker.