JSON Flatten / Unflatten
Flatten nested JSON objects to dot-notation keys or unflatten them back.
POST
1 credit
/v1/json-flatten
curl -X POST "https://devtools.toolkitapi.io/v1/json-flatten" \
-H "Content-Type: application/json" \
-d '{
"data": {
"user": {
"name": "Alice",
"address": {"city": "Portland", "zip": "97201"}
}
},
"separator": ".",
"direction": "flatten"
}'
import httpx
resp = httpx.post(
"https://devtools.toolkitapi.io/v1/json-flatten",
json={
"data": {
"user": {
"name": "Alice",
"address": {"city": "Portland", "zip": "97201"}
}
},
"separator": ".",
"direction": "flatten"
},
)
print(resp.json())const resp = await fetch("https://devtools.toolkitapi.io/v1/json-flatten", {
method: "POST",
headers: {
"Content-Type": "application/json",
},
body: JSON.stringify({
"data": {
"user": {
"name": "Alice",
"address": {"city": "Portland", "zip": "97201"}
}
},
"separator": ".",
"direction": "flatten"
}),
});
const data = await resp.json();
console.log(data);# See curl example
Response
200 OK
{
"result": {
"user.name": "Alice",
"user.address.city": "Portland",
"user.address.zip": "97201"
},
"direction": "flatten",
"key_count": 3
}Try It Live
Live Demo
Response
Description
Flatten nested JSON objects to dot-notation keys or unflatten them back.
How to Use
1
1. Pass your JSON object in the `data` field. 2. Set `direction` to `flatten` (default) or `unflatten`. 3. Optionally change the `separator` (default is `.`).
About This Tool
JSON Flatten converts deeply nested JSON objects into flat key-value maps using dot-notation (or a custom separator). Unflatten does the reverse — rebuilding nested structures from flat keys.
Useful for config management, database storage, CSV export, and comparing nested objects by their leaf values.
Why Use This Tool
- Config export — Flatten nested YAML/JSON configs for environment variables
- Database storage — Store nested objects as flat key-value rows
- Diff comparison — Compare two nested objects by their flattened keys
- CSV conversion — Flatten before exporting nested data to CSV
Frequently Asked Questions
How are arrays handled during flatten?
Arrays are flattened with numeric indices: `items.0.name`, `items.1.name`. Nested objects inside arrays are recursively flattened.
Can I use a different separator?
Yes — set `separator` to any string up to 10 characters, e.g. `__` or `/`.
Start using JSON Flatten / Unflatten now
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