JSON Key Extractor
Extract every unique key or key path from a JSON document, with a count of how many times each one occurs. Switch between bare key names and full array-normalized paths to audit schema consistency across a dataset.
Input
Key names dedupe by bare key regardless of nesting. Full paths show where each key lives, collapsing array indices into [] so repeated array items count toward the same path.
Output
| # | Key | Count |
|---|---|---|
| No data yet | ||
Guides
The JSON Key Extractor reads a JSON document and pulls out every key it contains, ranked by how often each one occurs. It's the fastest way to see what fields actually exist in a payload, spot inconsistent field names across an API response, or audit a large dataset's schema without reading every line by hand.
Two extraction modes
- Unique key names — collapses every key to its bare name, regardless of where it sits in the structure. Useful for a quick inventory of every field name used anywhere in the document.
- Full paths (array-normalized) — shows the dotted path to each key (
user.name,items[].sku), with array indices collapsed to[]so the same field across many array elements counts as one path instead of one row per index. The count then tells you how consistently that field is present across the array — a count lower than the array length flags a missing field on some items.
How to use it
- Paste your JSON into the input box — the table updates live as you type.
- Pick a mode from the dropdown to switch between key names and full paths.
- Use the copy or download button to export the table as CSV for a spreadsheet or report.
Common uses
- API developers auditing a response payload for consistent field naming.
- Data engineers checking whether every record in a JSON array shares the same schema before loading it into a pipeline.
- QA and support teams quickly seeing what fields a log entry or webhook payload actually contains.
Is my JSON private?
Yes. All parsing and extraction happens locally in your browser — your JSON is never uploaded to a server.
What counts as a "key"?
Only property names of JSON objects. Array indices are not keys, which is why array-mode paths use [] rather than a per-index number — otherwise every array of any length would produce one row per index instead of one row per field.