Free online JSON deduplicator. Remove duplicate elements from a JSON array by comparing full JSON representations. Preserves first occurrence order. Runs locally in your browser.
100% Local
How to Use the JSON Deduplicator
Paste a JSON array into the input box. Click Deduplicate and duplicate elements are removed, keeping only the first occurrence of each unique value. Use Clear to reset both panels.
How duplicates are detected
Each element is serialized to its JSON string representation
Two elements are duplicates if their JSON strings match exactly
Order is preserved — first occurrence is kept
Works on nested objects and arrays within the array
Features
Full deep-equality comparison via JSON serialization
Reports original and unique element counts
Handles arrays of any size
All processing runs locally in your browser. Your data is not uploaded to any server.