Developer toolsJSON Formatter
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Format and inspect JSON in one workspace

Paste or upload JSON, validate syntax, pretty-print or minify the result, sort object keys, and inspect nested structures in a searchable tree.

How to use this tool

  1. 1

    Add JSON

    Paste JSON, load the included sample, or upload a .json or .txt file.

  2. 2

    Choose an action

    Pretty-print, minify, or validate the current input.

  3. 3

    Inspect

    Use output tabs and tree search to review nested data.

  4. 4

    Export

    Copy the current output or download it as a JSON file.

What it can do

Validation feedback

See parser messages with line and column information when it can be determined.

Pretty and minified output

Create readable or compact JSON from the same input.

Tree explorer

Expand nested arrays and objects and search their keys or values.

Formatting options

Set indentation, sort object keys, and add a trailing newline.

Useful for

  • Debugging API responses
  • Cleaning configuration files
  • Inspecting webhook payloads
  • Preparing compact JSON for transfer

Limits to know

  • Comments and trailing commas are invalid in standard JSON
  • The formatter does not execute or evaluate code
  • Extremely large JSON can use substantial browser memory

Private browser processing

This tool runs locally in your browser. TunerPage does not upload the working file or text to its servers.

Frequently asked questions

How do I find an invalid JSON error?

Validate the input to see the parser message and an estimated line and column when available.

Can I sort object keys?

Yes. Enable Sort keys before formatting.

Can I inspect nested data?

Yes. The tree view lets you expand and collapse nested objects and arrays.

Is JSON sent to a server?

No. Parsing, formatting, search, and downloads run locally.

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