What Is a Certificate Chain? SSL Trust Explained
By Nick Phillips
Learn what a certificate chain is and how it ensures SSL trust for your website. Discover its importance in maintaining secure connections!
Blog
Notes from the otter
Posts about SSL certificates, monitoring, and the small things that go quietly wrong on the web.
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What Is an SSL Certificate? A Small Business Guide
By Nick Phillips
Discover what an SSL certificate is and why it's vital for your small business. Enhance security, trust, and search rankings today!
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What Is a Certificate Authority? A Small Business Guide
By Nick Phillips
Discover what is a certificate authority and how it secures your online transactions. Learn why it's essential for your small business!
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10 Best SSL Certificate Monitoring Tools in 2026
By Nick Phillips
Discover the 10 best SSL Certificate Monitoring Tools for 2026 and ensure your site stays secure. Get alerted before issues arise!
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UptimeRobot vs pingping.io vs TrackSSL vs Certimon vs SSLreminder 2026
By Nick Phillips
Compare UptimeRobot, pingping.io, TrackSSL, Certimon, and SSLreminder to find the right SSL monitoring and uptime service for your needs.
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Why Short-Lived Certificates Need Monitoring in 2026
By Nick Phillips
Discover why short-lived certificates need monitoring in 2026. Learn the critical stakes for website owners and ensure your security today!
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Domain Certificate Mismatch Causes: 2026 Fix Guide
By Nick Phillips
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!
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SSL Expiry Notification Setup: A Practical Guide
By Nick Phillips
Learn how to set up SSL expiry notifications to prevent downtime and security warnings. Keep your site safe with our practical guide!
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SSL Certificate Installation Explained for Small Sites
By Nick Phillips
Master SSL certificate installation explained in our guide. Protect your small site, build trust, and secure user connections today!
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How to check an SSL certificate's expiration date (5 ways)
By Nick Phillips
Five reliable ways to read an SSL/TLS certificate's expiration date — browser, openssl, curl, an online checker, and a short Python snippet.
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Your connection is not private — what the warning actually means and how to fix it
By Nick Phillips
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").
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Wildcard vs SAN certificates — which one do you actually want?
By Nick Phillips
A practical decision guide for choosing between wildcard certs (*.example.com) and multi-domain SAN certs — including the security trade-offs nobody mentions.
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Reading an SSL certificate with openssl — a tactical reference
By Nick Phillips
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.
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90-day SSL certificates are coming — here's what that actually means for you
By Nick Phillips
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.
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SSL vs TLS — what's actually different, and which one are you using?
By Nick Phillips
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.
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SSL certificate monitoring tools, honestly compared
By Nick Phillips
A frank comparison of Otterwatch, UptimeRobot, BetterStack, StatusCake, Datadog Synthetics, and a homegrown cron — including the cases where each one is the right answer.
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What actually happens when your SSL certificate expires
By Nick Phillips
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.
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Why your Let's Encrypt auto-renewal silently failed (and how to catch it)
By Nick Phillips
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.
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Why do SSL certificates expire?
By Nick Phillips
A short explainer on why SSL/TLS certificates have an expiration date, why that date keeps getting shorter, and what it actually protects against.