JSON Tips & Guides
Practical articles for developers working with JSON, YAML, and API data.
JSON Parse Errors: Unexpected Tokens, End of Input, Commas, Quotes, and HTML
Diagnose JSON.parse errors by the input you actually received, including HTML, undefined, objects, trailing commas, bad escapes, control characters, truncated JSON, and extra data after a valid document.
18 min readFix JSON Online: Repair Rules, JavaScript Workflows, LLM Output, and Privacy
Repair invalid JSON safely, understand what an online fixer changes, add an explicit repair path in JavaScript, clean up LLM output, and keep sensitive payloads in the browser or on your machine.
20 min readHow to Format, Validate, Minify, and View JSON
Format and validate JSON with JavaScript, Python, jq, Prettier, VS Code, or a browser-local tool; then choose minified text, pretty output, or a tree view without silently changing the data.
19 min readHow to Stringify and Parse JSON in JavaScript
Use JSON.stringify and JSON.parse safely for requests, storage, BigInt, replacers, revivers, object coercion, source access, and TypeScript types without losing values or trusting unvalidated data.
20 min readHow to Convert Between JSON, CSV, XML, and YAML
Convert JSON, CSV, XML, and YAML safely with practical rules for tabular flattening, headers, types, attributes, repeated elements, namespaces, YAML schemas, and round-trip validation.
22 min readHow to Decode JWT, Base64url, and URL-Encoded Data Safely
Decode JWT claims, Base64 and Base64url bytes, and percent-encoded URL values locally; handle Unicode correctly and understand why encoding is neither encryption nor JWT verification.
19 min readCompare Two JSON Files with jq, Semantic Diff, and JSON Patch
Compare JSON by normalizing keys and whitespace, use jq to inspect and transform changes, and choose JSON Patch or JSON Merge Patch when the diff must become an API update.
21 min readWhat Is JSON? Syntax, Data Types, JavaScript Objects, and JSON Schema
Learn JSON syntax and data types, see valid examples, compare JSON with JavaScript objects, and use JSON Schema to validate real data contracts.
18 min read