JSON formatter and validator

Validate JSON and add indentation to make it easier to read.

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We do not send your file or text contents to a processing server. No account is needed and there is no daily operation quota. Individual tools have size limits to protect your device’s memory.

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How to use this tool

  1. Paste complete JSON without comments or trailing commas.
  2. Choose indentation and format.
  3. Inspect values and keys; syntax validation does not check an API schema.

An example you can verify

Find syntax errors and make a compact JSON response readable.

Example input

{"ok":true,"n":2}

SettingsIndentation: 2 spaces.

Expected result

{
  "ok": true,
  "n": 2
}

Use double quotes and avoid trailing commas. Very large numbers and duplicate keys follow JavaScript parser limitations.

Continue your task

Download the result or copy the text before opening another tool. Then load or paste it into the next step; content is not transferred automatically.

Review table data

Keep codes such as 001 intact when converting to JSON, inspect the data and export when ready.

  1. Convert CSV to JSON
  2. Inspect the JSONHere
  3. Export back to CSV

When opening the CSV in a spreadsheet, import code columns as text to preserve leading zeros.

Settings and limits

Paste JSON and choose 2 or 4 spaces of indentation. Quotes, separators and structures are validated before producing the result.

Frequently asked questions

Are numbers and duplicate keys preserved?

The browser’s JSON parser is used. Numbers beyond JavaScript precision can change; the last duplicate key is retained. Do not use this tool to preserve very large integers.

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