Articles & Guides
Useful resources for web developers and system administrators
Security
152-FZ Website Compliance Checklist (Russian Data Law)
Does your site comply with Russia's 152-FZ personal data law? Check the privacy policy, consent checkbox, cookie notice, data localization, RKN notice.
SSL/TLS
Cannot Verify Server Certificate or Identity: Causes, Fixes
Cannot verify the server certificate? The name does not match, it is expired or self-signed, the chain is incomplete or revoked, or your clock is wrong.
Security
Blocked by Content Security Policy: How to Fix CSP Errors
Blocked by CSP? Read the console error by directive (script-src, connect-src), then allow the source or use a nonce or hash, not unsafe-inline.
DNS
How to Connect a Domain to Hosting: Step by Step
Two ways to connect a domain to hosting: change the NS servers or add an A record. Step by step, how long DNS takes to update, and how to confirm it worked.
Monitoring
Check Your Website for Errors: What to Test and With What
Check your site for errors by category: broken links (404), server errors (5xx), mixed content, console errors, security headers and markup.
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.