# Otterwatch > Daily SSL certificate expiry and uptime monitoring. We email only when something changes; quiet otherwise. Free for 5 sites. Otterwatch watches your sites' SSL certificates and uptime and sends a friendly email 30 days before a certificate expires (and again at 7 days), or if a site goes down. Calm by design: quiet unless something needs your attention. ## Main - [Home](https://otterwatch.dev/): Product overview and sign-up. - [Free SSL check](https://otterwatch.dev/check): Instant one-off SSL certificate check for any domain. - [MCP server](https://otterwatch.dev/mcp): Remote Model Context Protocol server — lets AI agents (Claude, Cursor, …) check any domain's SSL/TLS certificate. Endpoint: https://otterwatch.dev/mcp (Streamable HTTP). - [Blog](https://otterwatch.dev/blog): Guides on SSL/TLS, certificate expiry, and uptime monitoring. ## Blog posts - [What Is a Certificate Bundle? SSL Trust Explained](https://otterwatch.dev/blog/what-is-a-certificate-bundle-ssl-trust-explained): Learn what a certificate bundle is and why it’s essential for your website's security. Ensure a safe user experience without warnings. - [SSL Debugging Checklist for Developers: 2026 Guide](https://otterwatch.dev/blog/ssl-debugging-checklist-for-developers-2026-guide): Use this essential SSL debugging checklist for developers to quickly identify certificate issues and speed up your troubleshooting process. - [Fix Expired SSL Certificates Quickly: A Practical Guide](https://otterwatch.dev/blog/fix-expired-ssl-certificates-quickly-a-practical-guide): Learn how to fix expired SSL certificates quickly with this step-by-step guide. Prevent browser warnings and secure your site instantly. - [Why E-Commerce Needs Certificate Monitoring in 2026](https://otterwatch.dev/blog/why-e-commerce-needs-certificate-monitoring-in-2026): Discover why e-commerce needs certificate monitoring in 2026 to prevent costly outages and ensure seamless customer access to checkout. - [SSL Certificate Expiry Alert Types: 2026 Guide](https://otterwatch.dev/blog/ssl-certificate-expiry-alert-types-2026-guide): Discover essential ssl certificate expiry alert types for 2026. Stay ahead of renewals and protect your website's security and uptime! - [Top 6 webstatus247.com Alternatives for 2026](https://otterwatch.dev/blog/webstatus247-com-alternatives-6): Explore 6 webstatus247.com alternatives to help you decide on the best SSL and uptime monitoring service for your needs in 2026. - [Signs Your SSL Certificate Is Failing: 8 Clear Warnings](https://otterwatch.dev/blog/signs-your-ssl-certificate-is-failing-8-clear-warnings): Discover the signs your SSL certificate is failing. Learn how to identify issues early to prevent site outages and protect your users. - [Why Expired SSL Kills Sales on Your E-Commerce Site](https://otterwatch.dev/blog/why-expired-ssl-kills-sales-on-your-e-commerce-site): Discover why expired SSL kills sales on your e-commerce site. Protect customer trust and revenue by keeping your SSL certificates up to date. - [SSL Certificate Best Practices for Small Business Sites](https://otterwatch.dev/blog/ssl-certificate-best-practices-for-small-business-sites): Discover SSL certificate best practices for small business sites. Learn how to automate renewal and secure your website effectively. - [What Is a Free SSL Certificate? A Clear Guide](https://otterwatch.dev/blog/what-is-a-free-ssl-certificate-a-clear-guide): Discover what a free SSL certificate is and its benefits for securing your website. Learn how to protect your site with zero-cost options! - [How to Avoid SSL Expiration Warnings: 2026 Guide](https://otterwatch.dev/blog/how-to-avoid-ssl-expiration-warnings-2026-guide): Learn how to avoid SSL expiration warnings with our 2026 guide. Protect your site from errors with automated renewals and monitoring tools. - [Top 5 sitehawk.io Alternatives 2026](https://otterwatch.dev/blog/sitehawk-io-alternatives-5): Discover 5 sitehawk.io alternatives for efficient SSL management and website monitoring. Find the best option for your needs today. - [Why SSL Affects Website Credibility: A Clear Guide](https://otterwatch.dev/blog/why-ssl-affects-website-credibility-a-clear-guide): Discover why SSL affects website credibility. Learn how SSL certificates boost user trust, improve security, and enhance search rankings. - [Why SSL Matters for Trust on Your Website](https://otterwatch.dev/blog/why-ssl-matters-for-trust-on-your-website): Discover why SSL matters for trust on your website. Secure your site and boost visitor confidence with an SSL certificate today! - [Common Certificate Deployment Errors: IT Troubleshooting Guide](https://otterwatch.dev/blog/common-certificate-deployment-errors-troubleshooting): Discover how to troubleshoot common certificate deployment errors. Prevent SSL handshake failures and ensure compliance with our expert guide. - [E-Commerce SSL Requirements Explained for 2026](https://otterwatch.dev/blog/e-commerce-ssl-requirements-explained-for-2026): Discover the e-commerce SSL requirements explained for 2026. Learn about HTTPS, TLS certificates, and PCI compliance essentials for secure transactions. - [Certificate Monitoring Integration Types: 2026 Guide](https://otterwatch.dev/blog/certificate-monitoring-integration-types-2026-guide): Explore certificate monitoring integration types to safeguard against SSL certificate expiry. Learn the best strategies for system reliability. - [SSL Certificate Types Explained for Website Owners](https://otterwatch.dev/blog/ssl-certificate-types-explained-for-website-owners): Unlock the mystery of SSL certificate types explained! Discover how to choose the right SSL certificate for your website’s security needs. - [SSL Certificate Renewal Explained: 2026 Guide](https://otterwatch.dev/blog/ssl-certificate-renewal-explained-2026-guide): Discover ssl certificate renewal explained. Learn essential steps, new validity rules, and automation tips to keep your website secure! - [What Is Certificate Expiry Detection for IT Pros](https://otterwatch.dev/blog/what-is-certificate-expiry-detection-for-it-pros): Discover what is certificate expiry detection and why it's crucial for IT pros. Prevent outages and ensure site reliability with effective monitoring. - [Certificate Expiration Check Script: A Practical Guide](https://otterwatch.dev/blog/certificate-expiration-check-script-a-practical-guide): Discover how to create a certificate expiration check script to automate SSL/TLS monitoring, avoid downtime, and maintain site reliability. - [SSL Expiration Consequences Explained for Site Managers](https://otterwatch.dev/blog/ssl-expiration-consequences-explained-for-site-managers): Discover the ssl expiration consequences explained for site managers. Learn how expired certificates impact security, revenue, and user trust. - [SSL Certificate Installation Steps: Server Guide 2026](https://otterwatch.dev/blog/ssl-certificate-installation-steps-server-guide-2026): Master the SSL certificate installation steps with our 2026 server guide. Safeguard your site, gain trust, and ensure browser security. Click to learn! - [Certificate Expiration Notification Explained for Site Owners](https://otterwatch.dev/blog/certificate-expiration-notification): Discover how a certificate expiration notification explained can save your website from outages. Learn the importance of timely renewals! - [SSL Certificate Monitoring in Your CI/CD Pipeline](https://otterwatch.dev/blog/ssl-certificate-monitoring-in-your-cicd-pipeline): Enhance your CI/CD pipeline with effective SSL certificate monitoring. Learn tools, automation tips, and troubleshooting for flawless security. - [The Role of Certificate Management Tools in SSL Security](https://otterwatch.dev/blog/the-role-of-certificate-management-tools-in-ssl-security): Discover the crucial role of certificate management tools in SSL security. Automate management, reduce risks, and ensure compliance effortlessly! - [What Is a Certificate Chain? SSL Trust Explained](https://otterwatch.dev/blog/what-is-a-certificate-chain-ssl-trust-explained): Learn what a certificate chain is and how it ensures SSL trust for your website. Discover its importance in maintaining secure connections! - [What Is an SSL Certificate? A Small Business Guide](https://otterwatch.dev/blog/what-is-an-ssl-certificate-a-small-business-guide): Discover what an SSL certificate is and why it's vital for your small business. Enhance security, trust, and search rankings today! - [What Is a Certificate Authority? A Small Business Guide](https://otterwatch.dev/blog/what-is-a-certificate-authority-a-small-business-guide): Discover what is a certificate authority and how it secures your online transactions. Learn why it's essential for your small business! - [10 Best SSL Certificate Monitoring Tools in 2026](https://otterwatch.dev/blog/10-best-ssl-certificate-monitoring-tools-in-2026): Discover the 10 best SSL Certificate Monitoring Tools for 2026 and ensure your site stays secure. Get alerted before issues arise! - [UptimeRobot vs pingping.io vs TrackSSL vs Certimon vs SSLreminder 2026](https://otterwatch.dev/blog/uptimerobot-vs-pingping-io-vs-trackssl-vs-certimon-vs-sslreminder): Compare UptimeRobot, pingping.io, TrackSSL, Certimon, and SSLreminder to find the right SSL monitoring and uptime service for your needs. - [Why Short-Lived Certificates Need Monitoring in 2026](https://otterwatch.dev/blog/why-short-lived-certificates-need-monitoring-in-2026): Discover why short-lived certificates need monitoring in 2026. Learn the critical stakes for website owners and ensure your security today! - [Domain Certificate Mismatch Causes: 2026 Fix Guide](https://otterwatch.dev/blog/domain-certificate-mismatch-causes-2026-fix-guide): Discover the top domain certificate mismatch causes and learn how to fix them quickly with our 2026 guide. Don't let errors block your access! - [SSL Expiry Notification Setup: A Practical Guide](https://otterwatch.dev/blog/ssl-expiry-notification-setup-a-practical-guide): Learn how to set up SSL expiry notifications to prevent downtime and security warnings. Keep your site safe with our practical guide! - [SSL Certificate Installation Explained for Small Sites](https://otterwatch.dev/blog/ssl-certificate-installation-explained-for-small-sites): Master SSL certificate installation explained in our guide. Protect your small site, build trust, and secure user connections today! - [How to check an SSL certificate's expiration date (5 ways)](https://otterwatch.dev/blog/check-ssl-certificate-expiration-date): Five reliable ways to read an SSL/TLS certificate's expiration date — browser, openssl, curl, an online checker, and a short Python snippet. - [Your connection is not private — what the warning actually means and how to fix it](https://otterwatch.dev/blog/self-signed-certificate-warning): A field guide to NET::ERR_CERT_AUTHORITY_INVALID, NET::ERR_CERT_DATE_INVALID, and friends — what each one means, why it's showing up, and how to fix it for real (not by clicking "Advanced"). - [Wildcard vs SAN certificates — which one do you actually want?](https://otterwatch.dev/blog/wildcard-vs-san-certificates): A practical decision guide for choosing between wildcard certs (*.example.com) and multi-domain SAN certs — including the security trade-offs nobody mentions. - [Reading an SSL certificate with openssl — a tactical reference](https://otterwatch.dev/blog/read-ssl-certificate-with-openssl): A practical cheatsheet for openssl s_client and x509 — get expiration, issuer, SANs, full chain, fingerprints, and more. With the flags that actually matter explained. - [90-day SSL certificates are coming — here's what that actually means for you](https://otterwatch.dev/blog/90-day-ssl-certificates-google): Apple and Google are pushing TLS certificate lifetimes down to 47 days by 2029. Why it's happening, what breaks, and what to do about it now. - [SSL vs TLS — what's actually different, and which one are you using?](https://otterwatch.dev/blog/ssl-vs-tls-difference): SSL and TLS aren't the same thing, but everyone uses the names interchangeably. Here's the honest version of the history, the protocol differences, and which versions you should actually be running. - [SSL certificate monitoring tools, honestly compared](https://otterwatch.dev/blog/ssl-certificate-monitoring-tools-compared): A frank comparison of Otterwatch, UptimeRobot, BetterStack, StatusCake, Datadog Synthetics, and a homegrown cron — including the cases where each one is the right answer. - [What actually happens when your SSL certificate expires](https://otterwatch.dev/blog/what-happens-when-ssl-certificate-expires): A concrete walkthrough of what visitors see, what search engines do, what stops working server-side, and roughly how long it takes for each of those things to bite. - [Why your Let's Encrypt auto-renewal silently failed (and how to catch it)](https://otterwatch.dev/blog/lets-encrypt-auto-renewal-failed): The most common reasons certbot renew runs cleanly but your certificate still expires — and the cheapest ways to make sure you notice before your visitors do. - [Why do SSL certificates expire?](https://otterwatch.dev/blog/why-ssl-certificates-expire): A short explainer on why SSL/TLS certificates have an expiration date, why that date keeps getting shorter, and what it actually protects against. ## Legal - [Terms](https://otterwatch.dev/terms) - [Privacy](https://otterwatch.dev/privacy)