Free Online JSON & Data Tools
Validate, format, repair, transform, and analyse JSON. Generate TypeScript interfaces, JSON Schemas, and convert to CSV, YAML, XML.
Featured JSON & Data Tools
About JSON & Data Tools
JSON (JavaScript Object Notation) is the universal data format for APIs, configuration files, and data exchange. Working with JSON efficiently requires a toolkit — and Multi-Toolkit provides 15 free JSON tools covering every common JSON workflow.
**Validation and Repair**
The JSON Validator parses JSON in real time, highlights errors with line numbers and column positions, and suggests fixes. The JSON Repair tool automatically fixes the most common problems: trailing commas, single quotes instead of double quotes, JavaScript comments, and truncated documents.
**Formatting**
The JSON Formatter pretty-prints minified JSON with configurable indentation (2 spaces, 4 spaces, or tabs). The JSON Minifier does the opposite — removes all whitespace for production API payloads.
**Schema and Type Generation**
The JSON Schema Generator infers a valid JSON Schema (draft-07) from any JSON object — detecting types, required fields, string formats (email, date, UUID), and nested structures. The JSON to TypeScript tool generates TypeScript interface definitions, making API integration dramatically faster.
**Conversions**
Convert JSON to CSV, YAML, XML, Python dataclasses, and Java POJOs. Each converter is bidirectional where applicable.
**JSONPath Testing**
Test JSONPath expressions against your data interactively. Supports standard JSONPath syntax including recursive descent, array filters, and comparison operators.
How-To Guides
- 1Open the JSON Validator and paste your JSON.
- 2Errors appear instantly with line numbers and suggested fixes.
- 3If repairs are possible, click "Repair JSON" to auto-fix common issues.
- 4Review the diff to see exactly what was changed, then copy the fixed JSON.
- 1Copy an example JSON response from your API.
- 2Open JSON to TypeScript and paste the JSON.
- 3Set the interface name (e.g., "ApiResponse").
- 4Copy the generated TypeScript interfaces and add them to your project.
- 1Ensure your JSON is an array of objects (each object becomes a row).
- 2Open JSON to CSV and paste or upload your JSON.
- 3Choose your separator (comma, semicolon, or tab).
- 4Download the .csv file or copy the CSV text.
All JSON & Data Tools (16)
Frequently Asked Questions
What is the difference between JSON validation and JSON repair?
Validation checks if JSON is syntactically correct and reports errors. Repair attempts to automatically fix common errors like trailing commas and single quotes to produce valid JSON.
Can JSON Schema be used for API documentation?
Yes. JSON Schema is widely used for API documentation, request/response validation, and code generation in tools like Swagger/OpenAPI.
What JSON formats can I convert to?
Multi-Toolkit supports JSON to: CSV, YAML, XML, TypeScript interfaces, Python dataclasses, and Java POJOs. Reverse conversions (YAML to JSON, CSV to JSON, etc.) are also supported.
What JSONPath syntax is supported?
The JSONPath Tester supports: $ (root), . (child), [] (subscript), * (wildcard), .. (recursive descent), and filter expressions ?(@.field > value).
Is there a size limit for JSON files?
There is no hard limit. Processing happens in your browser, so very large files (10MB+) may be slower depending on your device. Most API responses and config files are well within comfortable range.