Let Compress

Format JSON

Beautify JSON with readable indentation directly in your browser.

Browser-only processing: your JSON is formatted locally and never uploaded.

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About JSON Formatter

JSON Formatter makes JSON easier to read by adding indentation and line breaks while keeping the data unchanged. It is useful for API responses, configuration files, debugging, and code review. Formatting happens in your browser so sensitive JSON stays local.Before emailing a PDF, open the downloaded copy and check fine text at the intended viewing size. The tool can reduce image detail; its target size is not guaranteed. If forms, signatures or searchable text matter, keep the original PDF.

What should I check before downloading?

Before emailing a PDF, open the downloaded copy and check fine text at the intended viewing size. The tool can reduce image detail; its target size is not guaranteed. If forms, signatures or searchable text matter, keep the original PDF.

  • Compare the downloaded file’s quality and actual size.
  • Savings vary by file. Some tools return the original if the output is larger; check the resulting format and size.
How to Format JSON Online
  1. 1
    Paste JSON into the editor

    Copy your JSON object or array into the input panel.

  2. 2
    Choose indentation and format

    Pick the indentation size you want and run the formatter to generate readable output.

  3. 3
    Copy or download the result

    Review the formatted JSON, then copy it or save it as a JSON file.

Frequently Asked Questions

Does formatting change my JSON data?

No. Formatting only changes whitespace and indentation, not the keys, values, or structure.

Can I choose different indentation sizes?

Yes. You can switch between several indentation sizes before formatting the JSON output.

Is this JSON formatter private?

Yes. The formatting runs locally in your browser, so your JSON is not sent to our servers.

What happens if the JSON is invalid?

The tool shows that the JSON is invalid and reports the error location when the browser provides it.

Why Choose Let Compress?
  • Compare the downloaded file’s quality and actual size.
  • Savings vary by file. Some tools return the original if the output is larger; check the resulting format and size.

References & Resources

Authoritative specifications and references for the file formats this tool works with.

RFC 8259 - The JSON Data Interchange Format

The IETF standard that defines JSON syntax.

ECMA-404 - The JSON Data Interchange Syntax

The Ecma standard that first specified JSON.

JSON.org

The original JSON resource site by Douglas Crockford.

Text processing tools for encoding, formatting, and transformation. Fast and free.