Data Formats & Encoding
Almost every program has to read data written by another, and that only works because both sides agree on a format. This cluster covers the formats and encodings you meet constantly — the ones behind API responses, config files, spreadsheets, and the text on every web page.
Understanding them turns a class of baffling bugs — garbled characters, “unexpected token” errors, data that grows a third larger for no obvious reason — into problems you can diagnose in seconds. Start with whichever format you're wrestling with, and use the linked tools to format, validate, or convert as you read.
Guides in this topic
What Is JSON? A Plain-English Guide (and How to Fix Common Errors)
Understand what JSON is, how its syntax works, and how to quickly fix the most common JSON errors — trailing commas, single quotes, unquoted keys, and more.
Base64 Encoding Explained: What It Is and When to Use It
What Base64 actually does, why it makes data ~33% larger, common uses like data URIs and email attachments, and the security myths worth knowing.
Character Encoding: Unicode and UTF-8 Explained
Why text sometimes turns into garbled symbols, what Unicode and UTF-8 actually are, the difference between characters, code points, and bytes, and how to fix mojibake.
YAML Explained — and How It Compares to JSON
What YAML is, why it's popular for config files, how its indentation-based syntax works, the gotchas to watch for, and when to choose YAML over JSON.
What Is XML? Tags, Attributes, and How It Works
A plain-English introduction to XML — elements, attributes, nesting, and well-formedness — plus how it differs from HTML and where it's still used today.
The CSV Format Explained (and How to Fix Common Problems)
How CSV files really work, why commas and quotes cause trouble, the encoding and delimiter pitfalls that break spreadsheets, and how to avoid them.
URL Encoding Explained: Percent-Encoding and When You Need It
What URL encoding (percent-encoding) is, why spaces become %20 and other characters get escaped, reserved vs. unreserved characters, and when to use it.
Other guide topics
Text & Writing
Guides for working with text — case conventions, word counts and readability, URL slugs, cleaning up messy text, and character encoding.
Images & Media
Guides to working with images for the web — compression, choosing formats, resizing and cropping, and the metadata hidden inside photos.
PDF & Documents
Guides to editing and organizing PDF files — merging, splitting, compressing, and converting — all without uploading your documents.
Web & Developer
Guides to the building blocks of web development — JWTs, timestamps, HTTP status codes, regular expressions, and color formats.
Security & Privacy
Practical guides to protecting your accounts and data — strong passwords, two-factor authentication, and keeping private information out of the files you share.
Device & Hardware Testing
Guides to checking your hardware — screens, keyboards, mice, cameras, microphones, and sensors — with browser tests that need no installation.