Category: Developer tools
JSON Array Deduplicator
Remove duplicate items from a JSON array by value or by key
Remove duplicate entries from a JSON array. Compare items by their full value, or give a key path such as id or user.email to deduplicate objects by a single field. Runs entirely in your browser.
1 of 3 item(s) removed as duplicates.
[
{
"id": 1,
"name": "Ada"
},
{
"id": 2,
"name": "Grace"
}
]Everything on this page is processed in your browser. Nothing is uploaded.
What this tool does
An API response or exported dataset often contains an array with repeated entries, whether identical objects or objects that only agree on one identifying field. This tool keeps the first occurrence of each item and drops the rest, comparing either the item's full serialized value or, when you give a key path, just the value at that path, so records duplicated by id or by a nested field like user.email are both handled.
How to use it
- Paste a JSON array of primitives or objects.
- Leave the key path blank to compare whole items, or enter a path such as id or user.email to dedupe by that field.
- Read the deduplicated array and how many items were removed.
Privacy
This tool runs entirely in your browser. Your input is never uploaded, stored or shared — closing the tab removes it.
Frequently asked questions
- How does deduplication work without a key path?
- Each item is compared by its full JSON text, so two objects are only treated as duplicates when every field matches.
- What does a nested key path like user.email do?
- It reads that field from each object before comparing, so items are deduplicated by that one value even if the rest of the object differs.
- Which occurrence of a duplicate is kept?
- The first one in the array. Every later item with the same value or key is removed.