JSON to CSV Converter
Turn a JSON array into a spreadsheet-ready CSV in seconds. Flatten nested objects, pick your delimiter, and download instantly — free.
How to Use the JSON to CSV Converter
- 1
Paste your JSON array (an array of objects) into the editor above.
- 2
JSON Flash auto-detects all keys and generates a preview of the CSV header row.
- 3
Choose your delimiter: comma (default), semicolon, tab, or a custom character.
- 4
Toggle "Flatten nested objects" to expand dot-notation keys or keep them as JSON strings.
- 5
Click "Convert" and then "Download CSV" to save the spreadsheet-ready file.
Key Features
Smart Flattening
Nested objects are flattened to dot-notation columns automatically (e.g., user.address.city → "user.address.city").
Custom Delimiters
Choose comma, semicolon, tab, pipe, or any single character as the cell delimiter — essential for European locales.
Heterogeneous Arrays
Handles arrays where different objects have different keys. Missing values become empty cells automatically.
Instant Download
Download the CSV directly from your browser. Open it in Excel, Google Sheets, or any data tool immediately.
Why JSON Flash?
- Processes entirely in your browser — no data uploaded to a server.
- Handles heterogeneous arrays where objects have different key sets.
- Configurable nested-object flattening strategy.
- Custom array join separator for cell values containing arrays.
- Pro plan supports files up to 100 MB with non-blocking streaming.
Frequently Asked Questions
How do I convert JSON to CSV?
Paste your JSON array into the editor above, choose your delimiter (comma, semicolon, or tab), and click Convert. JSON Flash flattens each object into a row and uses the union of all keys as the CSV header.
What JSON structure is required for CSV conversion?
The root must be a JSON array of objects (e.g., [{}, {}, {}]). Each object becomes one row. If the objects have different keys, missing values are represented as empty cells.
How are nested JSON objects handled?
By default, nested objects are flattened using dot notation (e.g., address.city becomes a column named "address.city"). You can switch to JSON-stringify mode to keep nested objects as escaped JSON strings in a single cell.
Can I choose a custom delimiter?
Yes. JSON Flash supports comma (standard CSV), semicolon (common in European locales), tab (TSV), and pipe-delimited formats. You can also type any custom single-character delimiter.
Can I open the CSV directly in Excel or Google Sheets?
Yes. Download the CSV file and open it in Excel, LibreOffice Calc, or import it into Google Sheets. For Excel, use semicolon delimiter if your locale uses commas as decimal separators.
What happens to arrays inside the JSON objects?
Nested arrays are joined with a pipe character (|) by default, so the cell reads "value1|value2|value3". You can change the array join separator in the settings panel.
Is there a file size limit?
Free users can convert JSON files up to 5 MB. Pro users can convert files up to 100 MB with streaming mode that avoids blocking the browser.
Can I reverse the conversion — CSV to JSON?
Yes. Use the CSV to JSON tool (linked below) to convert a CSV file back into a JSON array, with automatic type detection for numbers, booleans, and null values.
Related Tools
Unlock Pro — unlimited AI, 10 MB files, API access
Starting at $4/mo · 14-day money-back guarantee
- ✦Convert files up to 100 MB with streaming
- ✦Batch convert multiple JSON files to CSV
- ✦Custom column ordering and renaming
- ✦Auto-detect number and boolean types in output
- ✦API access for automated pipeline conversion