![\"How](\"https:\/\/www.dotcom-monitor.com\/blog\/wp-content\/uploads\/sites\/3\/2025\/12\/how-to-check-ssl-certificate-expiration-date.webp\")
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An SSL certificate expiration date tells you when the encryption certificate protecting your website will stop being valid. If the certificate expires, browsers will display security warnings and users may be blocked from accessing your site.<\/p>\n
You can check the SSL certificate expiration date in several ways:<\/p>\n
This guide explains step-by-step how to check SSL certificate expiration using different methods.<\/p>\n
SSL certificates are critical for securing websites, web applications, and APIs. They encrypt data in transit, verify server authenticity, and build user trust. However, SSL certificates have a limited lifespan; as of the industry update on March 15, 2026, all publicly trusted certificates are capped at a maximum of 200 days. When a certificate expires, visitors encounter security warnings, some services stop working, and it can affect search engine rankings.<\/p>\n
Monitoring SSL certificate expiration is essential to maintain secure and uninterrupted online services.\u00a0While there are many methods to check SSL certificates, Dotcom-Monitor<\/a> provides an easy way to monitor SSL\/TLS certificates for expiry, validity, and chain trust,<\/strong> an important component of full API observability<\/a>, giving teams peace of mind and preventing unexpected downtime.<\/p>\n This guide explains how to check SSL certificate expiration dates<\/b>, the role of SSL monitoring<\/a>, best practices for maintaining visibility, and how Dotcom-Monitor can help you stay ahead of SSL expiry issues.<\/p>\n SSL certificates are not permanent; they have defined expiration dates. Once a certificate expires, users visiting your website or interacting with APIs will see security warnings, which can reduce trust and even block access.<\/p>\n Keeping track of all SSL certificates manually can be challenging, especially when you manage multiple domains or subdomains. Dotcom-Monitor allows teams to monitor configured endpoints<\/b> continuously, providing alerts when a certificate changes or becomes invalid. This proactive approach helps avoid downtime and ensures uninterrupted secure connections.<\/p>\n Monitoring SSL certificates<\/a> is not just about preventing browser warnings\u2014it also improves reliability, avoids service interruptions, and gives IT teams confidence that critical systems are secure.<\/p>\n SSL certificates serve two main purposes: encryption and authentication. They secure data in transit and confirm that a website or server belongs to the organization it claims to represent. Each certificate includes key information: the domain name<\/b>, issuer<\/b>, validity period<\/b>, and chain of trust<\/b>.<\/p>\n Expiration is built into certificates as a security measure. It ensures that certificates are regularly renewed or replaced, maintaining the integrity of encryption keys and verifying domain ownership. Expired certificates are treated as untrusted by browsers and operating systems, leading to warnings and access blocks.<\/p>\n By understanding SSL expiration, IT teams can implement monitoring systems to catch potential issues early, avoiding disruptions to users or business services.<\/p><\/blockquote>\n SSL monitoring is the process of continuously checking configured endpoints for certificate validity. Dotcom-Monitor performs SSL monitoring by making connections to the specific domains or endpoints you configure<\/b>.<\/p>\n SSL monitoring focuses on:<\/p>\n When a monitored certificate changes or becomes invalid, Dotcom-Monitor can send alerts via email or webhooks, allowing IT teams to take action before users are affected.<\/p>\n This approach helps maintain secure connections, reduces downtime, and gives teams visibility over their SSL environment.<\/p><\/blockquote>\n For small-scale setups or one-off checks, manual verification is possible. There are multiple ways to view SSL certificate expiration:<\/p>\n Most browsers allow inspection of SSL certificates:<\/p>\n The \u201cValid to\u201d field shows when the certificate expires. After this date browsers will mark the website as insecure unless the certificate is renewed.<\/p>\n This method is simple but impractical for organizations managing multiple certificates or endpoints.<\/p>\n For developers and system administrators, tools like OpenSSL provide raw, detailed certificate data.<\/p>\n Example command:<\/p>\n This outputs both the notBefore (start) and notAfter (expiration) dates.<\/p>\n Best For:<\/strong> System administrators performing ad-hoc checks or writing basic scripts. While powerful, it lacks built-in alerting or centralized visibility.<\/p>\n This “Advanced” method involves integrating certificate checks directly into your CI\/CD pipelines (like GitHub Actions or GitLab CI) or infrastructure-as-code (Terraform).<\/p>\nIntroduction: Why Monitoring SSL Certificates Matters<\/h2>\n
Understanding SSL Certificates and Expiration<\/h2>\n
What Is SSL Monitoring?<\/h2>\n
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How to Check SSL Certificate Expiration Manually<\/h2>\n
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\n Method<\/strong><\/td>\n Difficulty<\/strong><\/td>\n Best For<\/strong><\/td>\n Scalability<\/strong><\/td>\n<\/tr>\n \n Browser Check<\/strong><\/td>\n Easy<\/td>\n Single websites<\/td>\n Very Low<\/td>\n<\/tr>\n \n OpenSSL\/CLI<\/strong><\/td>\n Medium<\/td>\n System admins<\/td>\n Low (Manual)<\/td>\n<\/tr>\n \n DevOps Scripts<\/strong><\/td>\n Advanced<\/td>\n CI\/CD Pipelines<\/td>\n High (Custom)<\/td>\n<\/tr>\n \n Monitoring Tools<\/strong><\/td>\n Easy\/Medium<\/td>\n Multiple domains<\/td>\n High (Automated)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n 1. Checking via Web Browser<\/h3>\n
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2. Using Command-Line Tools<\/h3>\n
openssl s_client -connect yourdomain.com:443 -servername yourdomain.com | openssl x509 -noout -dates<\/code><\/pre>\n3. Custom Scripting & DevOps Automation<\/h3>\n
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