JSON Tools — 9 Free Online JSON Utilities
Everything you need to work with JSON: pretty-print and beautify messy payloads, validate syntax with detailed error messages, minify for production, deep-compare two documents, and convert to XML, YAML, CSV, or Java classes. All tools run 100% client-side — your data never leaves your browser.
All JSON tools
JSON Formatter
Pretty-print and format JSON with 2-space indentation.
JSON Validator
Validate JSON syntax and detect errors instantly.
JSON Minifier
Compact JSON into a single line by removing whitespace.
JSON Compare
Deep-compare two JSON objects and highlight differences.
JSON to XML
Convert JSON objects to well-formed XML documents.
JSON to POJO
Generate Java POJO classes from a JSON object.
JSON to YAML
Convert JSON to clean, human-readable YAML format.
YAML to JSON
Parse YAML and convert it to formatted JSON.
JSON to TypeScript
Generate TypeScript interfaces from any JSON sample.
Frequently asked questions
- Are these JSON tools really free?
- Yes. Every JSON tool on ToolsForDevs Pro is 100% free with no sign-up, no rate limits, and no ads in the tool UI.
- Is my JSON data sent to a server?
- No. All JSON formatting, validation, conversion, and comparison runs entirely in your browser using JavaScript. Your data never leaves your device, which makes these tools safe to use with private or sensitive payloads.
- What's the difference between formatting, beautifying, and pretty-printing JSON?
- They mean the same thing — taking a single-line or minified JSON string and re-indenting it with newlines and spaces so it's easier to read. Our JSON Formatter uses 2-space indentation by default.
- Can I convert JSON to other formats?
- Yes. We support JSON ⇄ XML, JSON ⇄ YAML, JSON → CSV, and JSON → Java POJO classes. Each converter handles nested objects and arrays.
- How do I fix invalid JSON?
- Use the JSON Validator to see the exact line and message of the syntax error. The validator also has an auto-fix toggle that repairs common issues like trailing commas, single quotes, and unquoted keys.
- Is there a size limit on the input?
- There's no enforced limit, but practical limits depend on your browser's memory. Multi-megabyte JSON files work fine in modern browsers; very large files may slow the UI down.