What is a JSON formatter?
A JSON formatter parses JSON text and rewrites it with consistent indentation and line breaks. This makes nested objects and arrays easier to read without adding new data.
Tools
JSON Formatter / Validator
Format and validate JSON, explore nested data in a tree, or search the output. Copy or download the result without uploading your data.
Formatting, validation, tree view and search run locally in your browser. This tool does not upload or store your JSON, and analytics never include its contents.
JSON input
Paste up to 1,000,000 characters. Processing stays in this browser.
JSON output
Format or minify valid JSON to see the result.
This browser-based JSON formatter validates and rewrites JSON with two spaces, four spaces or tabs, or minifies it without extra whitespace. It preserves numeric literals exactly, including integers beyond JavaScript’s safe range. Search the line-numbered, syntax-highlighted output or inspect nested data in a collapsible tree, then copy or download the complete result.
How to format or minify JSON
- 1Paste a JSON object, array or value into the input field.
- 2Choose two-space, four-space or tab indentation and select Format, or select Minify for compact JSON. Both actions validate the input first.
- 3Search the code output, open nested values in the tree view, or use the line and column shown to fix an error. Copy or download the valid result when ready.
Format, validate and minify JSON
Each action starts with the same local JSON validator, but the output serves a different task.
| Task | What this tool does | When to use it |
|---|---|---|
| Format | Validates the input and writes it with two spaces, four spaces or tabs | Reading API responses, configuration and nested data |
| Validate | Reports the error line and column and can select that position in the input | Checking syntax before using a payload or file |
| Minify | Validates the input and writes compact JSON without indentation | Reducing unnecessary whitespace before copying data |
Common JSON syntax errors
Standard JSON syntax is stricter than a JavaScript object literal. These inputs will fail to parse.
| Problem | Invalid example | What to check |
|---|---|---|
| Single quotes | {'name':'Ada'} | Use double quotes around strings and object keys |
| Unquoted key | {name:"Ada"} | Put every object key in double quotes |
| Trailing comma | {"ok":true,} | Remove the comma after the final item |
| Comment | {"ok":true // note} | Remove // and /* */ comments |
| Missing separator or bracket | {"a":1 "b":2} | Check commas, braces, brackets and closing quotes |
Large-number safety: this tool validates JSON tokens and only rewrites whitespace. It does not convert numeric literals to JavaScript Number values, so unquoted large integers, decimals, exponents and negative zero keep their original digits and notation.
Browser-local JSON processing
Formatting, minifying and parsing run in this browser. This tool does not send the JSON you paste to a server for conversion.
Avoid pasting production secrets into any browser tool unless your organisation permits it. Browser extensions, screen sharing and copied output remain outside this tool’s control.
JSON formatter FAQ
What is the difference between formatting and minifying JSON?
Formatting adds line breaks with your choice of two spaces, four spaces or tabs. Minifying removes unnecessary whitespace and writes compact JSON.
How does this tool validate JSON?
Both Format and Minify use a strict JSON tokenizer and parser in your browser. Invalid input displays the error line and column, with a button that selects the relevant position.
Why do single quotes, trailing commas or comments fail?
They are not valid JSON syntax. JSON requires double-quoted strings and keys, does not allow a comma after the final item, and does not support comments.
Does formatting preserve every value exactly?
Yes. The formatter only changes whitespace between JSON tokens. String escapes, duplicate keys and numeric notation are kept as entered, including unquoted integers beyond JavaScript’s safe range.
Is the JSON I paste uploaded for processing?
No. Formatting, minifying and parsing happen in your browser, and this tool does not send the pasted JSON to a server for conversion.
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