JSON (JavaScript Object Notation) is the most common data format for APIs and configuration files. This guide shows how to format, validate, and debug JSON.
What is JSON Formatting?
Raw or minified JSON is hard to read — for example a single line packing every key together. Formatted (beautified) JSON adds proper indentation and line breaks so each key sits on its own line, making the structure clear at a glance.
How to Format JSON on ToolHub
Step 1: Open JSON Formatter. Visit toolhubpro.co/tools/json-formatter.
Step 2: Paste your JSON. Paste raw JSON into the editor. Even minified or broken JSON works.
Step 3: Click Beautify. JSON formats instantly with proper indentation and line breaks.
Step 4: Validate. Green means valid JSON; red shows an error with the exact location.
Step 5: Copy or download. Copy formatted JSON or download it as a file.
Common JSON Errors and Fixes
- Missing quotes on keys: {name: "John"} should be {"name": "John"}. All keys need double quotes in JSON.
- Trailing commas: {"a": 1, "b": 2,} should be {"a": 1, "b": 2}. JSON does not allow trailing commas.
- Single quotes instead of double: {'name': 'John'} should be {"name": "John"}. JSON requires double quotes only.
- Undefined values: {"result": undefined} should be {"result": null}. Use null instead of undefined.
JSON Validation
Valid JSON must use double quotes for strings, have no trailing commas, use null (not undefined, None, or NULL), use true/false (not True/False), and be properly nested with matching brackets.
Converting JSON to Other Formats
- JSON to CSV: useful for arrays of objects; import into Excel or Google Sheets.
- JSON to YAML: a more human-readable configuration format used in Docker, Kubernetes, and CI/CD pipelines.
- JSON to TypeScript: generate type interfaces automatically, saving time when working with API responses.
Frequently Asked Questions
Is my JSON data private? Yes. All processing happens in your browser. Your data never leaves your device.
Can it fix broken JSON? ToolHub can fix common issues like trailing commas and unquoted keys.
What is the maximum JSON size? Up to 10MB of JSON can be processed.