How to use JSON to CSV
- Paste or load a JSON array of flat objects or an array of arrays.
- Choose the output delimiter and an explicit nested-value policy.
- Preview the table, then download the generated CSV.
JSON to CSV Converter
Convert arrays of flat objects or arrays into correctly quoted CSV without uploads.
Private by design. CSV and JSON stay in browser memory in this tab. Nothing is uploaded, logged, saved, or executed.
Maximum 16 MB · 50,000 rows · 500 columns · 1,000,000 characters per cell.
Add a JSON array, then convert it.
Create CSV from two deliberately supported JSON shapes with deterministic object-column ordering.
How OpenFileTools processes it
Local processing, explicit choices.
One shared deterministic parser handles UTF-8, BOM, quoted fields, escaped quotes, embedded line breaks, and explicit delimiter modes. Cells render only as text, and output is created locally after review.
Quick technical summary
What this tool changes.
| Property | Behavior |
|---|---|
| Processing | Browser only; no image upload |
| Original | Never changed |
| Supported JSON roots | Array of flat objects; array of arrays |
| Object columns | Deterministic first-seen union of keys |
| Nested values | Reject or explicitly stringify as JSON text |
Convert only shapes that can become a table predictably
Arrays of flat objects and arrays of arrays map cleanly to CSV. Object keys are collected in deterministic first-seen order, missing keys become empty cells, and mixed root shapes are rejected instead of guessed.
- Nested objects or arrays are rejected unless you explicitly choose JSON stringification.
- CSV quoting protects delimiters, quotes, and line breaks.
- No spreadsheet data types are invented from text values.
Review CSV safety before opening untrusted data in a spreadsheet
CSV is plain text, but spreadsheet applications can interpret formula-looking cells when a file is opened. Use the preview to inspect headers and representative rows, and keep untrusted values inert until you deliberately move them into software that evaluates formulas.
Questions, answered.
Can I convert nested JSON to CSV?
Only when you explicitly choose to stringify nested values. The tool does not invent a recursive flattening scheme.
How are CSV columns ordered?
Object keys appear in the order they are first encountered across records.
Are commas inside text handled?
Yes. Fields are quoted and embedded quotes are escaped according to the CSV serializer.
Is the JSON uploaded?
No. Conversion stays in this browser tab.