What is JSON Formatter & Validator?
JSON Formatter & Validator is a free browser-based tool that formats, validates, and minifies JSON data instantly. Whether you’re debugging API responses, cleaning up config files, preparing JSON for production, or converting CSV data to JSON first, this json formatter online handles it without sending your data to any server. Everything runs locally in your browser, keeping your data private and secure. Need a deeper dive? Read our complete JSON formatter guide for best practices and real-world usage patterns.
When you need to validate JSON online, paste your data and click Validate — the tool pinpoints errors to the exact line so you fix problems in seconds, not minutes.
How to Use the JSON Formatter
- Paste your JSON into the input area
- Click Format to beautify with 2-space or 4-space indentation
- Click Minify to remove all whitespace for compact output
- Click Validate to check for syntax errors with line-specific feedback
- Use Copy to grab the formatted result to your clipboard
The validator shows exactly where errors occur, making it fast to fix malformed JSON from logs or API responses.
When to Use This Tool
- Debugging API responses: Format compact JSON from curl or Postman to read structure clearly — or use the validator to debug and fix invalid JSON syntax before it causes issues in production
- Cleaning config files: Standardize indentation across team JSON configs
- Preparing for production: Minify JSON to reduce file size before deployment
- Learning JSON syntax: Validate examples while learning JSON structure and rules
JSON Minify
JSON minify removes all whitespace — spaces, line breaks, and indentation — from JSON while keeping it fully valid. The result is the smallest possible representation of your data.
When to minify JSON:
- API responses: shave 20–40% off typical payloads before they hit the network
- Production builds: minified config files and data bundles load faster
- Embedding JSON in HTML or JS: compact form avoids accidental truncation
Click Minify in the JSON Tools tab to minify any valid JSON instantly. The output copies with one click.
XML to JSON Converter
Switch to the XML ↔ JSON tab to convert between XML and JSON in either direction.
XML to JSON — paste any XML document and click XML → JSON. The converter walks the XML tree with the browser’s built-in DOMParser, mapping elements to object keys, repeated elements to arrays, and attributes to an @attributes object.
JSON to XML — paste a JSON object and click JSON → XML. The converter wraps each key in a matching XML tag and handles nested objects and arrays recursively.
Common use cases:
- Converting legacy SOAP/XML API responses to JSON for modern frontends
- Transforming RSS or Atom feeds into JSON for JavaScript consumption
- Migrating data from XML-based configs (Maven
pom.xml, Android manifests) to JSON equivalents
FAQ
Does this json formatter online store my data?
No. All formatting, validation, and minification happens entirely in your browser. Your JSON never leaves your device.
Can I format large JSON files?
Yes. The tool handles JSON files up to several megabytes. Performance depends on your browser, but most typical API responses and config files process instantly.
What’s the difference between Format and Minify?
Format adds indentation and line breaks for readability. Minify removes all whitespace to create the smallest possible valid JSON, ideal for production environments or network transmission.
How do I validate JSON online?
Paste your JSON into the input field and click Validate. The tool parses it instantly, highlights the exact line with the syntax error, and shows a descriptive message. No account, installation, or server upload required — everything runs in your browser.
Why is my JSON invalid?
Common causes include trailing commas after the last array or object entry, single quotes instead of double quotes around keys or strings, unescaped special characters (like a bare backslash), and missing or mismatched brackets. Use the Validate button to pinpoint the exact line, then check our guide to debugging and fixing invalid JSON syntax for detailed fixes.
Is this json formatter online free?
Yes, completely free. No subscription, no sign-up, and no usage limits. The tool runs entirely in your browser with zero server costs or data transfer on your end, so it stays free indefinitely.
How do I convert XML to JSON online?
Click the XML ↔ JSON tab, paste your XML into the input area, and click XML → JSON. The converter uses your browser’s built-in DOMParser to walk the XML tree and output clean, indented JSON — no libraries, no server upload.
What is JSON minify used for?
JSON minify strips all whitespace (spaces, newlines, indentation) from JSON, reducing file size by 20–40% for typical payloads. It’s used before shipping JSON in API responses, config bundles, or frontend builds where every byte counts. The minified output is valid JSON — just without formatting.
Inspecting a JWT? The payload is JSON — decode it here. Try the JSON Formatter & Validator now — completely free, no sign-up required.