Format JSON for Use in JavaScript and Node.js
Overview
JavaScript developers work with JSON constantly: API responses, config files, test fixtures, and mock data. The formatter applies 2-space indentation (the JavaScript community standard per JSON.stringify default), validates against RFC 8259, and ensures proper UTF-8 encoding for all string values.
How to Use This Tool
Paste your JSON and click Format. The tool applies 2-space indentation and validates the structure. Copy the result into your JavaScript file, test fixture, or config. For embedding in a JS variable, wrap the output in backticks or use JSON.parse().
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PDF Tool →Frequently Asked Questions
What is the difference between JSON and a JavaScript object literal?
JSON requires double quotes on all keys and string values, no trailing commas, and no comments. JavaScript object literals allow single quotes, unquoted keys, trailing commas, and comments. JSON is a strict subset.
How do I embed formatted JSON in a JavaScript file?
For a JSON variable in .js, use: const data = JSON.parse('[your JSON string here]'). For a .json file imported via import data from './data.json', paste the formatted JSON directly into the file.
Should my JSON config files use 2-space or 4-space indentation?
2-space is standard in the Node.js and JavaScript ecosystem (used by npm, package.json, ESLint, Prettier defaults). 4-space is more common in Python projects. Match the convention of your existing codebase.