Free JSON Tools for Developers
Professional-grade JSON tools for formatting, validation, conversion, and data manipulation. All tools work offline in your browser - no uploads, completely secure and private.
Most Popular JSON Tools
JSON Formatter & Validator
Format, validate, and beautify JSON/JSONC with key sorting, inline arrays, duplicate key detection, and rich error detailsβall locally.
JSON to CSV Converter
Convert JSON arrays and objects to CSV format with customizable delimiters, headers, and data handling options.
CSV to JSON Converter
Convert CSV (Comma Separated Values) files to JSON format with advanced parsing options, data type detection, and flexible output structures.
JSON to XML Converter
Convert JSON data to well-formed XML with customizable formatting, attribute handling, namespace support, and structure validation.
XML to JSON Converter
Convert XML data to JSON format with customizable parsing options, attribute handling, namespace support, and intelligent structure conversion.
JSON to TypeScript Interface
Convert JSON data to TypeScript interfaces and type definitions. Automatically infer types, handle nested objects, and generate clean TypeScript code.
JSON Path Extractor
Extract specific values from JSON data using JSONPath expressions. Supports complex queries, filtering, and multiple output formats for data analysis and processing.
JSON Schema Validator
Validate JSON payloads against JSON Schema drafts using Ajv with configurable strictness, coercion, and error reporting β all offline in your browser.
Why Use JSON Tools?
API Development
Format and validate JSON responses from REST APIs, test endpoints, and debug API integration issues with proper JSON formatting.
Data Processing
Convert JSON to CSV, Excel, XML, and other formats. Transform and manipulate JSON data for analysis and reporting.
Code Generation
Generate TypeScript interfaces, validate JSON schemas, and create code templates from JSON data structures.
More JSON Tools
XML Formatter & Validator
Format, validate, minify, and convert XML with namespace-aware parsing, attribute sorting, JSON export, and instant error diagnostics β purpose-built for SOAP, RSS, and config workflows.
YAML Formatter & Validator
Format, validate, and convert YAML data with syntax checking, JSON conversion, and beautification options.
CSS Beautifier & Minifier
Format, beautify, and minify CSS code with proper indentation, validation, and optimization. Supports CSS3, media queries, and nested rules with comprehensive formatting options.
HTML Prettier Online
Format HTML code with prettier-style beautification online. Free HTML formatter with intelligent indentation, attribute sorting, validation, and minification β all in your browser.
JavaScript Beautifier & Minifier
Format, beautify, and minify JavaScript code with proper indentation, syntax validation, and optimization. Supports ES6+, JSX, and modern JavaScript features with comprehensive formatting options.
SQL Formatter & Beautifier
Format, beautify, and minify SQL queries with proper indentation, keyword formatting, and syntax validation. Supports multiple SQL dialects with comprehensive formatting options.
CSV Formatter & Validator
Format, validate, and convert CSV data with support for different delimiters, data type detection, sorting, filtering, and conversion to JSON or table format.
Data Format Transformer
Transform data between multiple formats including JSON, YAML, CSV, XML, TOML, INI, and Properties with structure preservation and advanced options.
Excel to JSON Converter
Free online Excel to JSON converter that safely converts Excel spreadsheets (.xlsx, .xls) to JSON format in your browser. No files uploaded to servers, works offline, supports multiple sheets and custom formatting options.
JSON to Excel Converter
Free online JSON to Excel converter that safely converts JSON data to Excel spreadsheets (.xlsx) or CSV format in your browser. No files uploaded to servers, works offline, supports nested object flattening and custom formatting options.
JWT Decoder & Validator
Inspect JSON Web Tokens with instant header/payload decoding, signature awareness, claim validation, and security warnings β all in-browser.
String Escape & Unescape
Escape and unescape strings for various programming languages and formats including JavaScript, JSON, HTML, XML, CSS, SQL, RegEx, URL, CSV, and Python.
Markdown Table Generator
Convert CSV, JSON, TSV, or manual data into beautifully formatted markdown tables. Support for sorting, alignment, and customization options.
API Response Formatter
Format, validate, and analyze API responses including JSON, XML, and raw HTTP responses with headers, status codes, and performance metrics.
Mock Data Generator
Generate realistic mock data for testing, development, and prototyping. Create users, products, orders, addresses, or custom data structures in multiple formats.
JSON Flattener
Flatten nested JSON objects to flat key-value pairs or unflatten back to nested structure with customizable delimiters and array handling
JSON Best Practices
β Do's
- β’ Use consistent naming conventions (camelCase or snake_case)
- β’ Validate JSON structure before production use
- β’ Use proper data types (strings, numbers, booleans)
- β’ Keep JSON structure flat when possible
- β’ Include version information for API responses
- β’ Use meaningful property names
β Don'ts
- β’ Don't use functions or comments in JSON
- β’ Avoid deeply nested structures (>3 levels)
- β’ Don't use undefined values (use null instead)
- β’ Avoid single quotes (use double quotes)
- β’ Don't expose sensitive data in JSON responses
- β’ Avoid extremely large JSON payloads
Frequently Asked Questions
What is JSON and why is it important?
JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format. It's widely used in web APIs, configuration files, and data storage because it's human-readable and easy to parse programmatically.
Are these JSON tools free to use?
Yes, all our JSON tools are completely free with no limitations on usage, file size, or features. No registration required and no hidden costs.
Is my JSON data secure when using these tools?
Absolutely. All JSON processing happens locally in your browser. No data is uploaded to our servers, ensuring complete privacy and security for your sensitive JSON data.
Can I use these tools offline?
Yes, once the page loads, all JSON tools work offline. You can format, validate, and convert JSON data without an internet connection.