Articles & Guides
Useful resources for web developers and system administrators
HTTP
429 Too Many Requests: How Long to Wait and How to Fix It
429 Too Many Requests means you hit a rate limit. How long it lasts, whose fault it is, how to fix it as a user or developer, and how to send Retry-After.
HTTP
403 Forbidden Error: Fixes for Visitors, nginx, Apache and APIs
403 Forbidden error: find who refused you (Cloudflare, nginx, Apache, WAF, app) from headers and logs, then fix it on Chrome, iPhone, Postman or your server.
HTTP
503 Service Unavailable: Causes and Fixes (nginx, IIS, WordPress)
What 503 Service Unavailable means, how long it lasts and how to fix it: nginx rate limits, PHP-FPM, IIS app pools, WordPress .maintenance, HAProxy, Kubernetes.
HTTP
HTTP 301 vs 302 Redirect: Differences and When to Use Each
301 vs 302 redirects compared: SEO impact, when to pick each, and setup examples for nginx, Apache, WordPress, PHP. Avoid common redirect mistakes.
HTTP
500 Internal Server Error: How to Fix It on nginx, Apache, IIS
500 Internal Server Error explained: whose fault it is, whether it fixes itself, real log strings and fixes for nginx, Apache, IIS, WordPress and Cloudflare.
HTTP
404 Not Found Error: Causes and Fixes for Chrome, nginx, Apache
A 404 Not Found error means the server works but the URL doesn't. Fix it in Chrome, nginx, Apache, IIS, WordPress or Next.js, and stop soft 404s for good.
DNS
DNS Records: How to Add, Check and Fix Them — Enterno.io
A practical guide to DNS records: add and edit them in any panel, get TXT right (SPF, DKIM, DMARC), verify with dig, and diagnose failures by symptom.
SSL/TLS
How to Check SSL Certificate and Never Miss Expiration
How to check an SSL certificate: via browser, OpenSSL, and online tools. Certificate types, trust chain explained, and automated expiration monitoring.
Monitoring
Top 10 Website Monitoring Services 2026: Features and Pricing
A comparison of 10 website monitoring services for 2026: an at-a-glance table (interval, Telegram, multi-region, price), a breakdown of each, and how to choose for your task.
Security
How to Check a Website for Malware: 4 Layers and a Cleanup
Check a website for malware: infection symptoms, external scanners, DevTools, hunting backdoors on the server and in the database, cloaking tests and a cleanup plan.