How does formatting help with debugging JSON?

Formatted JSON shows each key-value pair on its own line with clear nesting. It is much easier to spot a missing field, wrong data type, or unexpected null value in formatted output than in a compressed string.

Can I compare two versions of a JSON payload?

Yes. Format both versions with FixTools then paste them into the Diff Checker to see exactly what changed between them.

Is it safe to paste debug/internal JSON into FixTools?

Yes. FixTools runs entirely in your browser. No data is sent to any server, so you can safely paste internal or sensitive debug payloads.

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Format JSON for Debugging

When debugging JSON — from logs, API calls, or serialised data — readable formatting is the first step. FixTools formats your JSON instantly so you can see the full structure, find unexpected values, and isolate the problem without squinting at a compressed string.

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Cost: Free forever
Sign-up: Not required
Processing: In your browser
Privacy: Files stay local

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Collapsible tree view for deep nesting

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Syntax errors flagged with line numbers

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Compare before/after with Diff Checker

JSON Tool

JSON Formatter

All processing happens in your browser — your files are never uploaded to any server.

🚀Open JSON Formatter

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How to use this tool

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Paste your debug JSON payload and format it to see the full structure clearly.

How It Works

Step-by-step guide to format json for debugging:

1
Paste the problematic JSON
Copy the JSON from your log, console, or debug output and paste it into FixTools.
2
Format it
Click Format. FixTools indents the JSON and highlights the structure — or reports the exact syntax error if the JSON is invalid.
3
Inspect and fix
Read through the formatted JSON to identify the issue. Fix the source data and reformat to confirm the fix.