JSON Formatter
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Input
Output
Formatted JSON will appear here

What is this JSON Formatter?

This is a free, real-time JSON formatter and validator that runs 100% in your browser. No data is sent to any server. It supports formatting (beautifying), minifying, sorting keys alphabetically, and real-time validation with line-accurate error messages.

How does JSON formatting work?

JSON.parse() converts your text into an in-memory JavaScript object, then JSON.stringify() renders it back with proper indentation. This also validates the JSON as a side effect " any syntax errors are caught and displayed with the exact character position.

Is my data safe?

All processing is done entirely in your browser's memory using JavaScript. No data is sent to any server. When you close this tab, the data is gone. This makes it safe to use with API keys, tokens, or private configuration files.

What does "Sort Keys" do?

It recursively sorts all object keys alphabetically throughout the entire JSON structure. Useful for comparing two JSON objects for differences or enforcing consistent key ordering in config files.

What is JSON minifying?

Minifying removes all whitespace, newlines, and indentation from valid JSON. The result is functionally identical but smaller " useful for reducing payload size in HTTP API responses or configuration files.

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How to Use This Tool

Compare two JSON objects to find differences in structure, values, and keys. Identify what changed between API versions or config updates.

  1. Format your first JSON object with "Sort Keys" enabled and copy the output.
  2. Clear the input, paste your second JSON object, format it with "Sort Keys" as well.
  3. Compare the two formatted outputs side by side in your text editor or a diff tool.
  4. Sorted keys ensure structural differences are aligned line-by-line for easy comparison.
  5. Missing keys, changed values, and added fields become immediately visible when both outputs use identical key ordering.

What Is JSON Compare and Diff Tool?

JSON comparison involves checking two JSON objects for differences in their structure (keys), values, and ordering. This is essential when debugging API changes, verifying configuration updates, or testing data transformations.

The "Sort Keys" feature is critical for JSON comparison. Without sorted keys, objects with identical data but different key ordering appear different in a line-by-line diff. Sorting both objects first eliminates false positives from key ordering.

This tool helps you prepare JSON for comparison by formatting both objects with consistent indentation and sorted keys, making them ready for any diff tool (VS Code, Beyond Compare, diff command).

Why You Need This

Use cases for JSON comparison:

Pro Tips for Best Results

Frequently Asked Questions

How do I compare two JSON files?

Format both with Sort Keys enabled in this tool, copy each output, then paste them into a diff tool (VS Code, Beyond Compare, or the diff command). Sorted keys ensure identical structures align perfectly for line-by-line comparison.

Why do identical JSON objects sometimes look different?

JSON objects are unordered by specification. {"a":1,"b":2} and {"b":2,"a":1} are semantically identical but look different in text. Sort Keys resolves this by alphabetizing all keys in both objects.

Can this tool highlight specific differences?

This tool prepares JSON for comparison by formatting and sorting keys. For actual diff highlighting, paste the formatted outputs into VS Code or an online diff tool that highlights added, removed, and changed lines.