# ExpiryOwl > ExpiryOwl watches SSL certificates, domain registrations, DNS and uptime for web agencies and freelancers, and warns before anything expires or an automated renewal stalls. Plans: Free ($0, 5 hostnames), Freelancer ($9 a month, 50 hostnames), Agency ($29 a month, 250 hostnames), Agency Pro ($79 a month, 1,000 hostnames). ExpiryOwl is independently run, from Bahrain. Numbers on this site come from the app's own configuration: the ExpiryOwl facts page lists every plan, limit and check interval, and changes when they do. ## Facts - [Facts about ExpiryOwl](https://expiryowl.com/facts): plans and prices, what we check and how often, what is coming soon, what we don't do, and dates that matter, with sources. ## Free tools - [SSL certificate checker](https://expiryowl.com/tools/ssl-checker): Check any site's SSL certificate: expiry date, days left, issuer, SANs, chain trust and hostname match, plus whether its automatic renewal looks stalled. - [Domain expiry checker](https://expiryowl.com/tools/domain-expiry-checker): Look up a domain's expiry date, registrar, transfer lock, RDAP statuses and nameservers straight from the registry. Free, no signup. - [Bulk SSL checker](https://expiryowl.com/tools/bulk-ssl-checker): Check SSL certificates for up to 25 hosts at once. Days left, expiry, issuer and problems in one table, with CSV export. Free and unauthenticated. - [Find subdomains from certificate logs](https://expiryowl.com/tools/subdomain-certificate-finder): Find every subdomain that has had a public SSL certificate, straight from Certificate Transparency logs, with the latest expiry date for each host. - [47-day certificate readiness checker](https://expiryowl.com/tools/47-day-readiness-checker): Score how ready a domain is for 47-day SSL certificates: we find its hosts in CT logs, check each certificate and list the ones renewed by hand. ## Guides - [47-day SSL certificates: the schedule and what agencies should do](https://expiryowl.com/guides/47-day-ssl-certificates): Public TLS certificates drop from 398 days to 47 by March 2029. The exact dates, what changes for agencies, and a checklist to get ready. - [Let's Encrypt no longer sends expiry emails. What to do instead](https://expiryowl.com/guides/lets-encrypt-expiry-emails-ended): Let's Encrypt stopped sending expiry notification emails on 4 June 2025. Why it stopped, what to use instead, and how to spot a failed renewal early. - [ACME Renewal Information (ARI): how renewal windows work](https://expiryowl.com/guides/acme-renewal-information-ari): ARI (RFC 9773) lets a CA tell ACME clients when to renew. How the renewal window and certID work, which clients support it, and how to query it. - [How to check an SSL certificate's expiration date](https://expiryowl.com/guides/check-ssl-certificate-expiration): Check when an SSL certificate expires with a browser, openssl, curl or PowerShell, check many hosts at once, and avoid the SNI and chain mistakes. - [Domain expiry monitoring: what really happens when a domain lapses](https://expiryowl.com/guides/domain-expiry-monitoring): How gTLD domains expire, the grace and redemption periods ICANN requires, RDAP instead of WHOIS, and a checklist for agencies holding client domains. - [What happens when an SSL certificate expires](https://expiryowl.com/guides/what-happens-when-ssl-expires): What browsers, APIs, mobile apps and mail servers do when a TLS certificate expires, two outages with primary sources, and how to recover and prevent it. - [Find every subdomain with Certificate Transparency logs](https://expiryowl.com/guides/find-subdomains-certificate-transparency): Every publicly trusted certificate is logged in public CT logs. How to search them with crt.sh and Cert Spotter, and what agencies should do with the results. - [SSL monitoring for agencies: a playbook for 20 to 500 client sites](https://expiryowl.com/guides/ssl-monitoring-for-agencies): Inventory, renewal ownership, ACME, shrinking certificate lifetimes, alert routing and client reporting, for agencies looking after 20 to 500 client sites. ## Comparisons - [An UptimeRobot alternative that watches certificates](https://expiryowl.com/alternatives/uptimerobot): UptimeRobot and ExpiryOwl compared on price, SSL and domain expiry alerts, channels and status pages, with every UptimeRobot fact sourced. - [A TrackSSL alternative for agencies that also watch domains](https://expiryowl.com/alternatives/trackssl): TrackSSL and ExpiryOwl compared on pricing, certificate limits, domain expiry, alert channels and API access, with each TrackSSL fact linked. - [A Hyperping alternative for agencies focused on expiry dates](https://expiryowl.com/alternatives/hyperping): Hyperping and ExpiryOwl compared on price, free plan, SSL and domain expiry checks, alert channels and status pages, each fact sourced. - [An OnlineOrNot alternative for certificate expiry](https://expiryowl.com/alternatives/onlineornot): OnlineOrNot and ExpiryOwl compared on pricing, SSL checks, domain expiry, alert channels, API and status pages, with each fact linked. - [A StatusCake alternative with renewal-overdue warnings](https://expiryowl.com/alternatives/statuscake): StatusCake and ExpiryOwl compared on price, SSL and domain monitor limits, check intervals, alerts and API, with each StatusCake fact sourced. - [A Better Stack alternative for expiry monitoring only](https://expiryowl.com/alternatives/better-stack): Better Stack and ExpiryOwl compared on pricing model, free plan, SSL and domain expiry checks, alert channels and API, each fact sourced. - [A Red Sift Certificates Lite alternative for agencies](https://expiryowl.com/alternatives/red-sift-certificates-lite): Red Sift Certificates Lite and ExpiryOwl compared on price, discovery, scan frequency, expiry alerts and domain checks, every fact sourced. ## Developers - [REST API reference](https://expiryowl.com/docs/api): monitors, certificates, domains and incidents as JSON, with API keys. - [MCP server for AI assistants](https://expiryowl.com/docs/mcp): ask an AI assistant about your own portfolio over the Model Context Protocol. - [Webhooks](https://expiryowl.com/docs/webhooks): HMAC-signed incident payloads, with Zapier, Make and n8n recipes. ## Optional - [Pricing](https://expiryowl.com/pricing): plan table and pricing questions. - [Changelog](https://expiryowl.com/changelog): what shipped, by date. - [Privacy policy](https://expiryowl.com/legal/privacy): what we store, for how long, and which services see a monitored hostname.