Free Nested JSON to CSV Converter
for flattened spreadsheet-ready output.
Convert nested JSON into flat CSV instantly with this free online converter. No accounts. No uploads. No telemetry.
Paste your nested JSON
Generated CSV
id,user.name,user.address.city,user.address.zip,active,tags.0,tags.1
1,Alice,Montreal,H2X,true,frontend,react
2,Bob,Sacramento,95823,false,backend,nodeSupported
- Single nested JSON objects
- Arrays of objects
- Nested objects with dot notation keys
- Arrays flattened with indexed keys like
items.0.name - Primitive values such as strings, numbers, booleans and nulls
Automatically handled
- CSV escaping for commas, quotes and line breaks
- Header generation from all discovered flattened keys
- Mixed row shapes with empty cells for missing values
- Valid JSON detection in real time
Not supported yet
- JSON file uploads
- Very large file streaming
- Custom CSV delimiters such as semicolon
- Array explosion into multiple relational rows
- Advanced schema mapping options
Free online nested JSON to CSV converter
This tool works as a nested JSON to CSV converter, a JSON flattener, and a quick way to turn structured JSON into spreadsheet-ready CSV output.
It is useful when you need to convert API responses, exported documents, logs, analytics payloads, or database results into something that opens cleanly in Excel or Google Sheets.
Developers, analysts, and product teams often work with JSON payloads that contain embedded objects and arrays. This converter flattens those nested values into CSV columns using dot notation keys.
Everything runs locally in your browser, so your data is not uploaded or stored anywhere.
Example
[
{
"id": 1,
"user": {
"name": "Alice",
"address": {
"city": "Montreal"
}
}
}
]Paste this nested JSON into the converter above to instantly generate a flat CSV output with column names such as user.name and user.address.city.
Flatten nested JSON to CSV online
Use this converter to quickly flatten nested JSON objects and arrays into a CSV format that is easier to inspect, export, share, or open in spreadsheet tools.
Common use cases
- Convert API responses into CSV for Excel or Google Sheets
- Flatten MongoDB or Firebase exports into tabular data
- Prepare analytics payloads for spreadsheet review
- Transform structured logs or app data into CSV output
How it works
The converter parses your JSON input, recursively walks through nested objects and arrays, then builds flat key paths for every value it finds.
Those flattened keys become CSV column headers, while each object or array item becomes a row when possible.
The conversion runs entirely in your browser, so your data stays local and is never uploaded anywhere.
How are arrays handled in nested JSON to CSV?
Arrays are flattened with indexed keys such as items.0.name and items.1.name, which keeps the output in a single CSV row when possible.
This makes the output practical for spreadsheet workflows, even though it is different from a relational-style export where arrays are exploded into multiple rows.
FAQ
What is a nested JSON to CSV converter?
A nested JSON to CSV converter flattens structured JSON objects and arrays into a CSV format that can be opened in spreadsheets or used in tabular workflows.
Does this flatten nested objects and arrays?
Yes. The tool flattens nested objects with dot notation and handles arrays with indexed keys.
Is this JSON to CSV tool safe?
Yes. Everything runs in your browser and your JSON is not uploaded.
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