Guides

JSON guides & tutorials

JSON guides with worked examples. They cover formatting and converting JSON, JSON Schema, JSONPath and JWTs. Each guide links to the tool that does the job.

25 guides · updated 2026-10-01

How-to guides

Step-by-step answers to everyday JSON tasks.

How to format and beautify JSONPretty-print JSON with the right indentation in the browser, VS Code, JavaScript, jq and Python.6 min read How to minify JSON (and when you should)Minifying JSON removes whitespace between tokens to shrink payloads. How it works, when to do it, how it interacts with gzip, and code for JS, Python and jq.7 min read How to fix JSON syntax errors and JSON.parse SyntaxErrorThe most common JSON syntax errors, with before/after fixes, exact JSON.parse SyntaxError messages by browser, and how to read line and column numbers.15 min read How to escape and unescape JSON stringsEscape and unescape JSON strings: the required escapes, quotes, \uXXXX, embedding JSON in JSON, and how to avoid double-escaping bugs.9 min read How to compare two JSON files (JSON diff)Compare JSON files by structure, not text. Find added, removed and changed keys, ignore key order and array noise, and write diffs as JSON Patch.8 min read How to generate mock JSON data for testingGenerate realistic mock JSON data from a field spec with an online generator, Faker libraries or JSON Schema Faker. Covers seeds and keeping PII out.7 min read How to sort JSON keys alphabetically and make JSON canonicalSort JSON keys alphabetically for clean diffs and stable hashes. Why key order has no meaning in RFC 8259, and what canonical JSON means.7 min read How to open a JSON file on Windows, Mac and onlineWays to open and read a .json file: browsers, text editors, VS Code, an online viewer, jq and Python on the command line, and Excel for tables.6 min read

Concepts and deep dives

The standards, formats and specs behind JSON.

What is JSON? A beginner's guide to JavaScript Object NotationWhat JSON is, the six value types it supports, an annotated example, where you will see it, and how to read and validate it.6 min read JSON Schema: a complete guide with examplesJSON Schema draft 2020-12 from the ground up: core keywords including const, combinators, $ref reuse, and how to generate and validate schemas in code.7 min read JSONPath cheat sheet: syntax, filters and examplesA JSONPath reference for JSON queries: root, wildcards, recursive descent, slices and filters, with a sample document and an expression table.10 min read Understanding JWTs: structure, claims and verificationHow a JWT is built, what each registered claim means (including jti), how HS256 and RS256 signing work, and the verification mistakes that lead to auth bypasses.8 min read JSON data types explained with examplesJSON has exactly six data types. Here is what each one allows, how they map to JavaScript and Python, and the precision and null bugs that show up in production.8 min read Base64 encoding explained: format, examples and URL-safe Base64How Base64 turns binary into text, with a worked example, the standard and URL-safe alphabets, padding, and why it is not encryption.8 min read What is URL encoding? Percent-encoding, %20 and + explainedHow percent-encoding works, why spaces become %20, when + means a space, and when to use encodeURIComponent instead of encodeURI.8 min read Does JSON support comments? How to add comments to JSONJSON has no comment syntax. Why it was left out, the errors you get, which config files accept comments anyway, and how to keep notes without breaking a parser.6 min read JSON array of objects: syntax, examples and how to use itWhat a JSON array of objects looks like, the mistakes that make it invalid, and how to read, filter and convert one in JavaScript, Python and a spreadsheet.7 min read jq cheat sheet: filters, select, map and examplesEvery common jq filter on one page, each tested against the same sample file: selecting, filtering, reshaping, grouping, formatting output and the flags you need.9 min read

Format comparisons

JSON compared with other data formats, and when to use each one.

YAML vs JSON: differences and when to use eachHow JSON and YAML differ in syntax, comments, anchors, tooling and security, and a simple rule for choosing between them.6 min read JSON vs XML: differences and when to use eachHow JSON and XML differ in data model, size, parsing and schema validation, and where each format still fits today.8 min read JSON vs CSV: how and when to convert between themJSON is a tree and CSV is a table. When to use each, how to flatten nested JSON into CSV columns, and how to convert back safely.7 min read JSON5, JSONC and NDJSON explainedWhat JSON5, JSONC and NDJSON each add to JSON, real examples, and why standard parsers reject all three.8 min read

JSON in your language

Parse, generate and type JSON in JavaScript, Python and TypeScript.

Working with JSON in JavaScript: parse, stringify and moreJSON.parse and JSON.stringify in depth, plus reviver and replacer callbacks, dates, BigInt, deep copies and safe parsing.6 min read Working with JSON in Python: the json modulePython's built-in json module: parsing, serializing, pretty-printing, the type mapping, custom encoders and reading NDJSON.6 min read JSON to TypeScript: how to generate types from JSONTurn a JSON sample into TypeScript interfaces with nested objects, arrays, optional props and unions, and see why you still need runtime validation.9 min read