Guides
Practical, plain-English guides for developers — each one explains a concept and embeds the relevant tool so you can try it as you read.
How JWT authentication works
A plain-English guide to JSON Web Tokens — structure, signing, and verification — with a decoder built in.
GuideJSON vs YAML: which to use for config
When to choose JSON or YAML for configuration — readability, comments, types, and tooling — with a live converter.
GuideHow to compare two JSON objects
Find what changed between two JSON payloads — added, removed, and changed keys — without scanning by eye.
GuideHow to convert JSON to CSV (including nested data)
Turn a JSON array of objects into spreadsheet-ready CSV, and handle nested fields cleanly.
GuideWhat is Base64 encoding (and when to use it)
How Base64 turns binary into text, why it is not encryption, and where it actually belongs.
GuideMD5 vs SHA-256 vs SHA-512: which hash to use
The differences between common hash functions, why MD5 and SHA-1 are unsafe for security, and what to use instead.
GuideURL encoding explained (percent-encoding)
Why URLs use %XX escapes, which characters need encoding, and how to encode query parameters safely.
GuideRegex cheatsheet with live tester
The regular-expression syntax you actually use — anchors, classes, quantifiers, groups — with a tester to try each one.
GuideHow to compare two CSV files
Spot added, removed, and changed rows between two CSV exports without opening a spreadsheet.
GuideHow to format SQL for readability
Make dense SQL readable with consistent keyword case and indentation — and why it matters for review.
GuideUnix time explained: epoch, milliseconds, and timezones
What a Unix timestamp is, how seconds vs milliseconds differ, how timezones fit in, and the 2038 problem — with a live converter.
Guidepx vs rem in CSS: which to use and how to convert
When to use px, rem, or em, why rem is better for accessibility, and how the px ÷ root-size math works — with a live converter.