Web & APIs
Web & API Guides
The web runs on a handful of encodings and conventions that everyone uses and almost nobody reads the specification for. These guides go through them properly: what the three parts of a JSON Web Token contain, why the payload is encoded rather than encrypted, and what verifying a signature does and does not prove. What Base64 is for, why it inflates data by a third, and how the URL-safe variant differs from the standard alphabet. How percent-encoding decides which characters are safe in a query string, a path segment and a form body — three subtly different rules that produce three different results for the same input. Regular expressions get the same treatment, from character classes and quantifiers to the engine differences that make a pattern work in Python and fail in JavaScript. The aim throughout is to replace copied snippets with a working mental model.
6 guides in this topic · All posts
URL Encoding Explained: %20 vs +, Reserved Characters, When to Encode
What percent-encoding does, which characters are reserved, why forms use + for a space, and how encodeURIComponent, encodeURI and URLSearchParams differ.
9 min read · Updated 2026-09-11Sass vs SCSS vs LESS vs Stylus: Choosing a CSS Preprocessor
How Sass, SCSS, LESS and Stylus differ in syntax and modules, what native CSS nesting and custom properties replaced, and how to migrate between dialects.
9 min read · Updated 2026-09-11HTML Entities Explained: When to Escape &, <, > and Quotes
Which characters to escape in HTML text, attributes, URLs and scripts, how named, decimal and hex references differ, and why you keep seeing &amp;.
9 min read · Updated 2026-09-11How to POST JSON with curl (Without Quoting Pain)
POST JSON with curl correctly: the Content-Type header, shell quoting on Linux/Mac vs Windows, sending from files with @, and pretty-printing responses.
2 min read · Updated 2026-06-04How to Decode a JWT (and Why Decoding Isn't Verifying)
Decode any JWT in seconds: the three-part structure, Base64url quirks, code and no-code methods — and the critical difference between decoding and verifying.
2 min read · Updated 2026-06-04What is Base64? Encoding Explained Without the Mystique
How Base64 works: 3 bytes become 4 characters, why the = padding exists, where it's used (JWT, data URIs, K8s secrets) — and why it's NOT encryption.
2 min read · Updated 2026-06-04