Softonic

JSON Formatter

Step 1 / 4 JSON formatter

Paste JSON from an API response, config file, webhook, or log sample, then choose Format, Minify, or Validate. The formatter expands nested objects and arrays with 2 or 4 spaces, the minifier removes unnecessary whitespace, and the validator checks that the text is valid JSON before you copy the result.

How to format JSON

  1. 1

    Paste your JSON

    Add a complete JSON value: an object, array, string, number, boolean, or `null`.

  2. 2

    Choose an action

    Use Format for readable output, Minify for compact output, or Validate for a syntax check.

  3. 3

    Pick indentation

    For formatted output, choose 2 spaces for web projects or 4 spaces when that matches your repository style.

  4. 4

    Copy the result

    Review the parser message or formatted output, then copy the result back into your editor, API client, or documentation.

What this JSON formatter does

  • Format JSON: turns compact input such as {"a":1,"b":[1,2,3]} into readable, indented JSON.
  • Minify JSON: removes whitespace that is only there for readability, useful for compact examples, embeds, and transport payloads.
  • Validate syntax: checks whether the pasted text can be parsed as JSON. This is a syntax check, not a JSON Schema validation.
  • Handle any JSON root value: objects and arrays are common, but a JSON text may also be a string, number, true, false, or null.
  • Keep the workflow simple: paste, choose the action, review the output, and copy the result.

What it intentionally does not change

  • It does not repair malformed JSON automatically. The parser message tells you what to fix.
  • It does not accept JSONP wrappers such as callback({...}).
  • It does not accept comments or trailing commas from JSONC unless you remove them first.
  • It does not sort object keys. Existing key order is preserved as much as the parser and serializer allow.
  • It does not validate business rules, required fields, or API schemas. Use a JSON Schema validator for that step.

Formatting choices

Situation Best action Why it helps
Reading an API response Format with 2 spaces Nested objects and arrays become easier to scan.
Matching a repository style Format with 2 or 4 spaces Consistent indentation keeps code reviews clean.
Embedding a payload in a request Minify Removes whitespace without changing the JSON values.
Checking copied data from logs Validate Confirms the pasted fragment is complete JSON before you reuse it.
Preparing API documentation Format Examples are easier for readers to inspect and copy.

JSON syntax issues this catches

Parser complaint Common cause What to do
Unexpected token ' at position X Single quotes around a key or string Use double quotes for JSON strings.
Unexpected end of JSON input Missing closing brace, bracket, or quote Check the end of the pasted text.
Unexpected token , at position X Trailing comma after the last item Remove the trailing comma.
Unexpected token a at position X Unquoted key, NaN, or undefined Quote keys and use valid JSON values only.
Unexpected token / at position X Comment copied from JSONC or JavaScript Remove // and /* */ comments before validating.

Practical tips

  • Format first when reviewing a response, then minify only when a compact payload is actually needed.
  • Validate before pasting JSON into docs, tickets, or API clients, especially when the source was a partial log line.
  • Keep indentation consistent with the surrounding project. Changing 2 spaces to 4 spaces across an existing file can create a noisy diff.
  • Avoid pasting secrets, production credentials, or customer data into any general-purpose web tool. Use your organization’s approved offline or internal formatter for sensitive payloads.

Frequently Asked Questions

No. This tool checks JSON syntax only. If you need to confirm required fields, allowed values, or object shapes, run the result through a JSON Schema validator after it parses cleanly.

Strict JSON does not allow comments or trailing commas. Remove JSONC-style comments and final commas before validating or formatting.

Use the style your project already uses. Two spaces are common in JavaScript and web configuration files; four spaces can be easier to read in some backend repositories.

Avoid pasting secrets, access tokens, credentials, or customer records into a general-purpose web formatter. For sensitive payloads, use an approved internal or offline tool.

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