Flatten JSON Array
Flatten nested JSON arrays into a single level instantly. Free online JSON array flattener with item counts before and a
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How to Use Flatten JSON Array
- Paste a nested array: Paste a JSON array containing nested arrays into the input box, or load the sample.
- Click Flatten Array: Press the Flatten Array button. All nesting is collapsed into a single-level array.
- Check the count: The output shows the item count before and after flattening. Copy the flat array.
About Flatten JSON Array
Flatten JSON Array merges nested arrays into a single-level array.
- Recursive Flattening: Any depth of nesting is collapsed into one flat array.
- Objects Preserved: Non-array values inside arrays are kept unchanged.
- Count Comparison: See the item count before and after flattening.
Perfect for charting libraries, databases and tools that require flat data.
Frequently Asked Questions
What does flattening a JSON array do?
It recursively merges nested arrays into one single-level array. For example [1, [2, [3]]] becomes [1, 2, 3].
What happens to objects inside arrays?
Objects are kept as-is — only nested arrays are flattened. The tool shows the item count before and after.
Why flatten arrays?
Many data tools, databases and charting libraries require flat arrays. Flattening makes nested API data easy to process.