JSON Formatter
Runs in your browser — your data is never uploaded.
Pretty-print minified or messy JSON into a readable, consistently indented document — and validate it at the same time. Choose 2-space, 4-space or tab indentation; if the input isn’t valid JSON, OkConverter tells you the exact line and column of the first error instead of a vague failure. Your data is parsed entirely in your browser, so API responses and config files with sensitive values never leave your machine.
0 characters · runs entirely in your browser
How to use JSON Formatter
- 1
Paste your JSON — minified, ugly or hand-edited — into the box.
- 2
Pick your indentation style (2 spaces, 4 spaces, or tabs).
- 3
Click “Format”. Fix any reported syntax error, or copy/download the pretty result.
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Frequently asked questions
Does it validate my JSON too?+
Yes. Formatting requires a full parse, so invalid JSON is caught immediately — and the error message includes the line and column where parsing failed, which makes missing commas and stray brackets quick to find.
Is my JSON uploaded anywhere?+
No. Parsing and formatting run entirely in your browser. That’s a real consideration for JSON — it often contains API keys, tokens, and customer data that shouldn’t be pasted into a server-backed tool.
Will it change my data or reorder keys?+
No. Only whitespace changes. Key order, values, and nesting are preserved exactly as parsed — the output is byte-for-byte equivalent JSON, just readable.
Can it handle large files?+
Yes — it comfortably handles multi-megabyte JSON, limited only by your browser’s memory. Everything stays local, so there’s no upload size cap.
What about JSON with comments or trailing commas?+
Those are JSON5/JSONC extensions, not standard JSON, so they’re reported as syntax errors — with the line number, making them easy to strip.