JSON to CSV Converter
Convert a JSON array, a single object, or a newline-delimited JSON (NDJSON) file to CSV in your browser, flattening nested fields automatically.
What this tool does
A one-step conversion with sensible defaults: nested objects become dotted-path columns, a list of plain values is joined into one text column, and the result downloads as CSV. Need to choose your own separator or join text? Use JSON Flattener instead — the same underlying flattening, with those controls exposed.
Nested data is never guessed at
A list of objects, or a list that mixes different types of values, cannot be flattened into columns without guessing a shape, so it is not: it is kept as its own JSON text in one cell, and the row count never changes because of it. Nothing here silently drops or restructures your data to force it into a table.
Browser-local processing
Conversion runs as a SQL query against your file inside DuckDB, running as WebAssembly in your browser. Your file is not uploaded. The exported CSV uses the same formula-injection neutralization as every other CSV export on this site.
Large files
This tool warns you above roughly 100 MB, warns more strongly above roughly 500 MB, and declines to open a file above roughly 2 GB rather than risk crashing the tab.
Related tools
- JSON FlattenerFlatten nested JSON into flat key paths, previewed before export.
- JSON ViewerValidate, search and explore any JSON document as a virtualized tree.
- CSV to JSONComing soonConvert CSV rows to a JSON array or newline-delimited JSON.
- JSON to ParquetConvert JSON records to typed Parquet, with nested structure preserved.