Guides
Color Converter & WCAG Contrast — A Designer's Guide
HEX, RGB, HSL conversion plus WCAG 2.1 AA/AAA contrast ratios — what they mean, when each test matters, and how to read the numbers.
6 min read
Encoding Encyclopedia: Base64, URL, JWT, and Beyond
Complete reference for Base64, URL encoding, HTML entities, JWT, Unicode, and character sets. Encoding vs encryption clarified, decision tree included.
20 min read
Free Finance Calculators — Mortgage, Loan, Tip, Compound Interest
A practical guide to free online finance calculators: tip splitter, compound interest, percentage discounts, and more. Pure-browser, no signup, no tracking.
7 min read
BMI, Calorie & Fitness Calculators — A Practical Guide
How to use BMI, BMR, and fitness calculators correctly. Metric vs imperial inputs, WHO categories, and where the formulas come from.
6 min read
Complete Guide to JSON in 2026
Deep dive into JSON: history, syntax, variants (JSON5, NDJSON, BSON), validation, performance, and security. With practical examples and 10+ FAQs.
18 min read
Everyday Utility Tools — Age, Unit Converter, GPA, and More
Small tools that save you a Google search: age in days, unit converter, GPA calculator, percentage math, reading time, and word count.
5 min read
Regex Mastery: From Beginner to Wizard
Master regular expressions: finite automata theory, JS flags, 30 common patterns, lookahead/lookbehind, catastrophic backtracking, Unicode, and performance.
20 min read