Developer Blog

Spot differences between two versions of code, config files, or any text — with side-by-side highlighting that makes changes obvious.

Learn regex step by step — from matching literal text to lookaheads and capture groups — with a live tester to validate every pattern.

Stop opening Excel for basic math. Calculate percentages, convert units, and do number base conversions right in your browser.

From case conversion to word counting to string escaping — the text tools that save developers time every single day.

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.

Master the five-field cron syntax, understand common scheduling patterns, and build or validate cron expressions with visual tools.

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.

Convert between bytes, temperatures, lengths, and more without opening a calculator app — purpose-built tools for developer workflows.

Stop writing throwaway scripts to convert between data formats. Here's a guide to CSV, JSON, YAML, and XML — plus instant converters for each.

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 bloats SVG files and how to strip metadata, comments, and unnecessary attributes — cutting file size by 30-60% instantly.

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.

Stop guessing which CSS layout system to use. Learn the clear rules for choosing between Flexbox and Grid — with visual playgrounds to practice.

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.