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JSON Formatter Online

Paste messy JSON, get readable output. Proper indentation and syntax highlighting in one click.

JSON Formatter

Use this tool directly in your browser — no signup required.

Use JSON Formatter

100% private — files are processed locally and never uploaded.

How to JSON Formatter Online

  1. 1

    Paste your JSON

    Copy raw JSON from an API response, log file, or database export and paste it into the input field.

  2. 2

    Format it

    Click format. The tool parses the JSON and outputs it with consistent 2-space indentation and line breaks.

  3. 3

    Copy or download

    Copy the formatted output to your clipboard or download it as a .json file.

Reading JSON Without Formatting Is Painful

API responses come back as a single line of compressed JSON. Config files from automated tools often have no indentation. Database exports dump everything flat. Trying to read nested data in that format is like reading a paragraph with no spaces between words.

Formatting adds line breaks after each key-value pair, indents nested objects and arrays, and visually groups related data. A 200-character single-line response becomes a structured, scannable document. You can immediately see the nesting depth, spot missing values, and understand the data shape.

This formatter processes everything client-side. Your JSON stays in your browser — useful when you're working with production data that shouldn't be pasted into third-party services.

Frequently Asked Questions

What indentation does the formatter use?

2 spaces per level by default. This is the most common convention in web development and matches what tools like Prettier produce.

Will it fix invalid JSON?

No. If the JSON has syntax errors (missing quotes, trailing commas, etc.), the formatter will show an error pointing to the problem location. Use the JSON validator tool for detailed error messages.

Is there a size limit?

Since it runs in your browser, the limit depends on your device's memory. JSON files up to 10-20 MB format without issues on most machines. Very large files may cause your browser tab to slow down.