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JSON Deduplicate — Remove Duplicate Keys & Values

Remove duplicate object keys (keep first or last) and deduplicate array values in JSON. Detect duplicates before cleaning — all client-side.

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JSON input
Deduplicated JSON

About this tool

Duplicate keysArray dedupeFirst/last keepDetection countFullscreen

How to use

  1. Paste JSON — duplicate keys in source are detected automatically.
  2. Choose keep first or last for duplicate keys.
  3. Enable array value dedupe if needed, then copy the cleaned JSON.

Examples

Duplicate keys

{"id":1,"id":2,"name":"Ada"}
{"id":2,"name":"Ada"} (keep last)

FAQ