Articles & Guides
Useful resources for web developers and system administrators
Monitoring
How to Check a Website for Errors: A Technical Checklist
How to check a site for technical errors by category: broken links, 5xx, mixed content, browser console, headers. What to check each with and in what order.
HTTP
How to Check a Site's Redirect Chain in a Minute
How to check a redirect chain and a link’s final address: a tool, curl, DevTools. What 301/302/307/308 mean and which chains are dangerous.
Security
DDoS Protection: How to Defend Your Site Before an Attack
The layers of DDoS protection: filtering proxy/CDN, WAF, rate limiting, hidden IP, capacity headroom. How defense differs for volumetric vs application attacks.
Monitoring
How to Check If a Website Is Down or It Is Just You
Tell whether a site is down for everyone or just you: check from outside, HTTP status, another device and network. What the result means and what to do.
Tools
How to Find Out What CMS (Engine) a Website Runs On
Which traces reveal a site’s CMS: the generator meta, /wp-content/ paths, headers, and cookies. An auto-detector and why the engine is sometimes hidden.
Infrastructure
How to Check If an Email Address Exists
Three levels of email verification: syntax, MX records, SMTP probe — and why a 100% check without sending is impossible. How to verify safely.
Domains
How to Check If a Domain Is Available in a Minute
Find out in a minute whether a domain is free or taken: WHOIS lookup, reading the answer, checking several zones, and what to do if the name is taken.
Domains
How to Find Out a Website's Hosting and IP Address
Find a site’s IP and hosting in a minute: the domain → A record → IP → ASN → network owner chain. Why a CDN shows only the proxy, not the real server.
Security
How to Check a Website for Fraud: 12 Signs of a Phishing Site
12 technical and behavioral signs of a fraudulent site: domain age, address spoofing, SSL details, legal info. A two-minute check with free browser tools.
Security
DDoS Attack: How to Tell and What to Do in the First Hour
Signs of a DDoS attack, a first-hour action plan, how to tell an attack from an outage, and how to prepare in advance. Log triage, anti-DDoS, rate limiting.