Performance
How We Measure HTTP Timing: DNS, TCP, TLS, TTFB Breakdown
847ms response time doesn't tell you much. Is it slow DNS? Network latency? The server itself? Here's how to break it down with Go's httptrace.
Upsonar Blog
Guides on domain management, SSL certificates, and keeping your websites online.
Domain Management
Why .dev, .app, .page (and 40+ Other TLDs) Don't Respond to WHOIS
If your domain monitoring tool only uses WHOIS, it can't check .dev, .app, .page and dozens of other TLDs. Here's why, and how RDAP fixes it.
SSL
Why Most SSL Certificate Monitors Are Blind (And How to Fix It)
InsecureSkipVerify skips all certificate validation. Your monitor says '53 days left' while users see browser warnings. Here's the two-step pattern that catches everything.
Monitoring
When 200 OK Doesn't Mean Everything Is OK
Your uptime monitor says everything is fine. Your users see a broken page. Here's why traditional monitoring lies and what actually works.
Domain Management
What Happens When Your Domain Expires (And How to Prevent It)
A complete timeline of domain expiration — from grace period to public auction. Learn the real cost of losing a domain and how to protect yourself.
Domain Management
Domain Expiration Monitoring: The Complete Guide
How to monitor domain expiration dates, choose between WHOIS and RDAP, and set up automated alerts so you never lose a domain.
Domain Management
WHOIS vs RDAP: The Future of Domain Lookups
WHOIS has been the standard for domain lookups since the 1980s. RDAP is its modern replacement. Here's what changed, why it matters, and which one you should use.