Free tools
JSON Formatter
Format nested JSON with readable indentation.
Processed in your browser. Your input is not uploaded.
Input
Paste JSON or read a local .json file. Choose indentation for the output.
Ctrl / Cmd + Enter to runResult
Your result will appear here.
About this tool
Make nested JSON easier to read without changing number literals or escaped strings. This formatter checks syntax before adjusting whitespace, which is useful when inspecting API responses, configuration files and long numeric identifiers.
When to use it
- Read nested API responses.
- Prepare readable configuration files.
- Compact JSON while preserving numeric IDs.
How to use it
- Paste JSON, read a local text file or load the example.
- Choose indentation or the compact one-line option.
- Format, review the output, then copy or download the JSON.
Input and output example
Input
{"id":9007199254740993,"items":[1,2]}Output
{
"id": 9007199254740993,
"items": [
1,
2
]
}Important details
- Input must be valid JSON, not JavaScript object notation or JSON with comments.
- Formatting preserves literal text; it does not sort keys or validate a business schema.
- Text files are limited to 1 MB; deeply nested or excessive output is rejected.
Frequently asked questions
Will long numeric IDs be rounded?
No. Formatting retains the original number literals rather than serializing parsed JavaScript numbers.
Does minifying change the values?
The compact option removes whitespace outside strings. String escapes and number literals remain intact.