#guides

Cut through the noise — here are the HTTP status codes you'll encounter in real development, what they mean, and when to use each one.

Two reference tables every web developer needs: the complete ASCII chart and a searchable MIME type lookup — both available instantly.

Discover what information is tied to an IP address — geolocation, ISP, timezone, and more — and how developers use IP lookups in practice.

Help search engines find and index your pages correctly with properly configured sitemap.xml and robots.txt files — generated in seconds.

Learn the essential Open Graph meta tags that control how your pages appear when shared on Facebook, Twitter, LinkedIn, and Slack.

Learn how HMAC works, where it's used in webhooks and APIs, and generate or verify HMAC-SHA256 signatures instantly.

Understand CIDR notation, subnet masks, and host ranges — with an interactive calculator that does the math for you.

Understand CSP directives, prevent XSS attacks, and generate production-ready Content-Security-Policy headers without trial and error.

Learn what makes a password truly secure, why length beats complexity, and generate cryptographically random passwords instantly.

Finally understand rwx, octal notation, and common permission patterns — with an interactive calculator to get chmod right every time.

Understand the three parts of a JWT, how signing works, and why you should never store sensitive data in tokens — plus decode any JWT instantly.

Understand percent-encoding, reserved characters, and why your URLs break — then fix them instantly with the right tools.

Learn what Base64 encoding actually does, when to use it, and when not to — plus encode and decode strings and images instantly.

Understand the cryptography behind SSH keys and generate a secure key pair directly in your browser — no terminal required.

Edit, annotate, merge, split PDFs entirely in your browser — nothing uploaded to any server.

Visual CSS generators for gradients, shadows, animations, and clip-paths — all free.

Compare Nginx and Apache configuration — performance, security, and generator tools.

Understand WCAG contrast ratios, AA vs AAA compliance, and how to test your colors.

Environment variables done right — validation, best practices, and common mistakes.

Master JSON manipulation with practical tips — from key sorting to schema validation.