How to Format, Validate & Compare JSON on Mac

Format, validate, and compare JSON on Mac

1. Open or paste your JSON Load a file or paste JSON straight into the editor. Large payloads open quickly in a native app.
2. Format it Reformat the JSON with consistent indentation so nested structure becomes readable at a glance.
3. Validate for errors Run validation to catch missing commas, unclosed brackets, and other syntax errors, with the problem location highlighted.
4. Compare two files Open a second file and use a side-by-side comparison to see exactly which values were added, removed, or changed.
5. Convert or generate Convert between JSON and XML, or generate code models from your structure when you need to move from data to implementation.

Why format JSON at all

Minified JSON is efficient for machines and unreadable for humans. Formatting it — adding consistent indentation and line breaks — turns a single dense line into a clear tree you can actually navigate and debug.

A native editor formats even very large payloads instantly, without the lag you hit when a browser tab tries to render megabytes of text.

Validation catches the errors you cannot see

A single missing comma or unbalanced bracket makes an entire JSON document invalid, and the error is easy to miss by eye. Validation parses the structure and points you straight to the offending line so you fix the cause instead of hunting for it.

That matters most when the JSON is an API response or config file that has to be exactly right to work.

Comparing versions and doing more

When a response changes between two runs, a side-by-side comparison shows precisely what moved — which is far faster than scanning two documents manually. Beyond comparison, the same workspace handles XML, sends REST requests, and generates code, so you are not switching between separate tools for related tasks.

And because it runs natively on your Mac, your data never leaves your machine the way it does with an online formatter.