Developer tools

JSON Formatter & Validator

Format, minify and validate strict JSON. See duplicate-key, numeric and Unicode risks before copying the result.

Inputs and files used by these developer tools stay in your browser.

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When to use it

Format, minify and validate strict JSON. See duplicate-key, numeric and Unicode risks before copying the result.

Before you export

Formatting is not JSON5 conversion and does not silently sort keys. Read warnings about duplicate keys or unsafe numbers instead of assuming every consumer preserves them.

How to use this tool

  1. Paste JSON or open a .json file, then choose indentation.
  2. Run the action and review errors, warnings or validation details.
  3. Copy or download the available result; reset clears the current task.

Supported input and output

Input
JSON
Output
JSON · Inspection report

Questions about this tool

Does formatting change large numbers?

The formatter preserves numeric text rather than rounding it through JavaScript numbers. It warns when a downstream parser may lose precision; pretty printing does not remove that risk.

Do my files or text leave this device?

Your source content is processed in this browser, not uploaded for processing. The browser may download a processing engine from Voice2Sub’s CDN. Those engine requests do not contain your source file.

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