About this tool
Inspect API payloads and configuration data with explicit validation evidence before copying or downloading normalized JSON.
JSON Formatter is most useful when raw payloads are technically valid but unreadable. Instead of pasting minified API responses into an editor and manually re-indenting them, you can validate, format, sort keys, and inspect nested structure in one place.
- Uses Microsoft jsonc-parser 3.3.1 offsets in strict mode to report syntax locations and reject comments, trailing commas, duplicate object keys, and unsafe integers before native parsing.
- Applies 1,000,000-character, 2,000,000-byte file, 200,000-node, 128-depth, and 2,000,000-character output limits with stale result protection.
- Creates 2-space, 4-space, tab, minified, recursively sorted, or lazy tree views and verifies a stable JSON round trip before copy or syntax-safe download.
How to use JSON Formatter
Paste a JSON payload, config object, or webhook sample into the panel above, then switch between formatted, minified, sorted, or tree views depending on the task. If parsing fails, use the error location to fix the payload first, then copy or download the cleaned output.
When this tool is useful
- Clean up minified API responses before debugging nested fields.
- Validate copied JSON config or webhook payloads before shipping changes.
- Reformat JSON for pull requests, docs, or support tickets.
Practical tips
- Check the error output first when pasted JSON fails to parse. One trailing comma or quote usually breaks the whole document.
- Use the formatter before diffing payloads so structural changes are easier to spot.
- Avoid sharing production secrets inside sample payloads when pasting data into any browser tool.
Examples you can test
Load an example, compare the result with the expected output, then replace it with your own input.
Format a compact API response
Example input
{"status":"ok","user":{"id":42,"roles":["admin","editor"]}}Expected output
{
"status": "ok",
"user": {
"id": 42,
"roles": [
"admin",
"editor"
]
}
}Formatting makes nested fields easier to inspect before a response is copied into a bug report, fixture, or documentation example.
Catch invalid JSON before shipping config
Example input
{
"enabled": true,
"limit": 10,
}Expected output
Invalid JSON: trailing comma near the final property.
A single trailing comma is enough to break strict JSON parsing, so validation should happen before sharing config values.
Validation checklist
- Confirm the input parses successfully before using formatted, sorted, or minified output.
- Remove secrets, tokens, and production personal data before pasting sample payloads.
- Use tree view for deeply nested payloads when a field is hard to find in plain formatted text.