Guides & deep dives
Everything we've learned about working with JSON — written down so you don't have to learn it the hard way.
How to Fix "Unexpected token" Errors in JSON
The "Unexpected token in JSON" error has a handful of common causes. Learn how to read the message, find the offending character, and fix invalid JSON fast.
How to Validate JSON with JSON Schema
JSON Schema describes the shape your data should take. Learn how to write a schema, validate a document against it, and read every error by its path.
JSONPath Explained: Query JSON with Examples
JSONPath is a query language for JSON — like XPath for XML. Learn the syntax (wildcards, recursive descent, slices, filters) with examples you can test live.
How to Generate TypeScript Types from JSON
Stop hand-writing types for API responses. Learn how to turn a JSON sample into TypeScript interfaces — including nested objects, arrays, and optional fields.
How to Escape and Unescape JSON Strings
When you need to embed JSON inside JSON, escaping is the answer. Learn what JSON string escaping does, when you need it, and how to reverse it cleanly.
Free, Ad-Free JSON Tools That Keep Your Data Private
JSON Toolkit is a completely free, ad-free suite of online JSON tools that runs entirely in your browser — no sign-up, no uploads, no tracking. Here's why it's different.
How to Convert JSON to YAML, CSV, XML & Markdown
A practical guide to converting JSON to YAML, CSV, XML, and Markdown — and back again — online and 100% in your browser. Learn which format to use and when.
How to Compare and Search JSON Files Online
Learn how to diff two JSON files and find or replace keys, values, and paths across a document — structurally, with regex support, entirely in your browser.
How to Format, Validate, and Repair JSON Online
A complete guide to cleaning up JSON: beautify and minify, validate against RFC 8259, pinpoint syntax errors, and auto-repair broken JSON — free and in your browser.
How to View and Explore Large JSON Files
Six ways to read JSON without drowning in braces: a syntax-highlighted viewer, a collapsible tree, a sortable table, a spreadsheet-style grid, a node-link graph, and a JSONL reader — all in your browser.
How to Format JSON: A Complete Guide
Learn how to beautify, minify, and sort JSON the right way — and why consistent formatting makes your data easier to read, diff, and debug.
JSON vs YAML: When to Use Each
JSON and YAML can represent the same data, but they shine in different places. Here's a practical guide to choosing between them — and converting losslessly.
Understanding JSON Diff: Comparing Data Structures
Comparing JSON is harder than comparing text. Learn the difference between line-based and structural diffs, and how to spot what actually changed.