LOCAL JSON FORMATTER
Format valid JSON for reading or compact transfer.
Pretty print or compact valid JSON with selectable indentation. Parsing and formatting run locally in your browser.
Valid JSON is formatted locally.
Review the output before copying it into another file or system.
How formatting works
The tool parses the input with JavaScript JSON.parse and serializes the resulting value with JSON.stringify. Pretty print adds the selected indentation; Compact removes optional whitespace while preserving JSON values. For example, {"name":"Ada"} becomes a multiline object in pretty mode or stays on one line in compact mode. Invalid JSON produces an error and clears the previous output.
Inputs are limited to 100,000 characters and 100 nested levels. Object key order follows JavaScript's JSON parsing and serialization behavior; this is not a canonical JSON signer or validator for a schema. Page content updated November 3, 2026.
Runs in your browser. No uploads. No account.
Good to know
Can I minify JSON?
Yes. Choose Compact to remove formatting whitespace while preserving the parsed JSON value.
Does this validate a JSON Schema?
No. It checks JSON syntax only. Use a schema validator when you need to check data against a separate schema.
Does formatting preserve the original text exactly?
No. The input is parsed and serialized, so whitespace and some textual number forms can change while the JSON value remains the same.
Is my JSON uploaded or saved?
No. Parsing and formatting run locally in this browser tab; the page makes no external data request for your input.
Is it free?
Yes, during beta. Optional usage-credit plans are coming soon. Payments are not available and no credits are required.
Sources
The tool uses JavaScript's JSON parsing and serialization methods. Source checked November 3, 2026.
How it works
1. Paste JSON or use the example. 2. Choose pretty print or compact output and an indentation style. 3. Format, review, then copy the result; processing stays in your browser.
Good to know
Can I minify JSON?
Yes. Choose Compact to remove formatting whitespace while preserving the parsed JSON value.
Does this validate a JSON Schema?
No. It checks JSON syntax only; use a schema validator to check data against a separate schema.
Does formatting preserve the original text exactly?
No. It parses and serializes the input, so whitespace and some number spellings can change while the value remains the same.
Is my JSON uploaded?
No. Parsing and formatting run locally in this browser tab, with no external input request or upload.
Is it free?
Yes, during beta. Optional usage-credit plans are coming soon. Payments are not available and no credits are required.
Methodology and limitations
Parse the input with JSON.parse, reject nesting beyond 100 levels, and serialize with JSON.stringify. Pretty mode uses two spaces, four spaces, or tabs; compact mode omits optional whitespace. Inputs are limited to 100,000 characters. This checks JSON syntax and formats the parsed value but does not validate a schema or produce canonical JSON.