JSON Formatter & Beautifier Online
Minified JSON from an API response or a log file is nearly impossible to read. This formatter takes compact JSON and produces a clean, indented version with 2-space indentation — or goes the other way and minifies verbose JSON to reduce payload size.
JConvert also validates your JSON as it formats. If there is a syntax error, you get a detailed message with the line number, column, and a suggestion for how to fix it.
No sign-up, no server — everything runs in your browser.
What this tool does
The formatter parses your JSON input using the native JSON.parse() method, then re-serializes it with JSON.stringify() using 2-space indentation. This simultaneously validates the JSON and produces consistently formatted output.
For minification, the tool strips all unnecessary whitespace, producing the most compact valid JSON possible — ideal for reducing payload size in APIs and storage.
Common use cases
- Beautifying minified API responses for debugging and inspection
- Validating JSON configuration files before deploying
- Minifying JSON payloads to reduce network transfer size
- Formatting JSON for documentation, wikis, or code reviews
- Quickly finding syntax errors in hand-edited JSON files
How to use JConvert
- Paste or upload your JSON into the input editor.
- Click Beautify to format with indentation, or toggle to Minify for compact output.
- Copy or download the formatted result.
Notes and limitations
- The formatter uses native JSON parsing, which means it strictly follows the JSON specification (RFC 8259).
- Trailing commas, single quotes, and unquoted keys are flagged as errors with helpful fix suggestions.
- Comments are not valid JSON and will cause a parse error. Use JSONC or YAML if you need comments.
- Very large files (several MB) may take a moment to format but will complete successfully.
- Maximum input size is 10 MB.
Privacy and security
Your JSON is parsed and formatted entirely in your browser. Nothing is transmitted to any server. This makes it safe for formatting API tokens, configuration secrets, and any sensitive data structures.
Example
Minified JSON input
{"name":"Alice","age":30,"address":{"city":"Paris","zip":"75001"}}Formatted JSON output
{
"name": "Alice",
"age": 30,
"address": {
"city": "Paris",
"zip": "75001"
}
}Ready to convert your data?
Open JSON FormatterFrequently Asked Questions
- Does the formatter validate my JSON?
- Yes. The tool parses your JSON with the native JSON parser, so any syntax errors are detected and reported with line numbers and suggestions.
- Can I minify JSON too?
- Yes. Switch the output format to JSON (Minified) to strip all whitespace and produce the most compact representation.
- What indentation does the formatter use?
- The formatter uses 2-space indentation, which is the most common convention in JavaScript and TypeScript projects.
- Are comments supported?
- No. Standard JSON does not support comments. If your file has comments (JSONC), remove them before formatting, or use a JSONC-aware editor.
- Does my data leave my browser?
- No. All formatting and validation is performed client-side. Your data stays on your machine.