CSV ↔ JSON Converter – Free Online Tool
Convert CSV files to JSON arrays and JSON arrays back to CSV instantly in your browser. Upload a file or paste text — no server, no registration.
Files are automatically deleted after processing. All conversion happens in your browser.
Upload CSV File
Drag & drop or browse files
First row used as keys — up to 20MB
Max file size: 20 MB
How to Use
Choose Direction
Select CSV → JSON or JSON → CSV using the toggle.
Upload or Paste
Drop your file onto the uploader or paste text directly.
Download Result
Preview the output and click Download to save the converted file.
Why Use Our Tool?
100% Private
All conversion happens in your browser — your data never leaves your device.
Bidirectional
Switch between CSV→JSON and JSON→CSV with one click.
RFC 4180 Compliant
Correctly handles quoted fields, embedded commas, and newlines.
No Registration
Free to use immediately with no account required.
Frequently Asked Questions
How does the CSV to JSON converter work?
Your CSV is parsed entirely in the browser. The first row becomes JSON keys, and each subsequent row becomes a JSON object. No file is uploaded to any server.
What format should my JSON be for JSON → CSV conversion?
The input must be a JSON array of flat objects, e.g. [{"name":"Alice","age":30}]. Nested objects are not supported for CSV output.
Are quoted fields and commas inside values supported?
Yes. The CSV parser correctly handles RFC 4180 quoted fields, including values that contain commas, quotes, or newlines.
Is there a file size limit?
Files up to 20MB are supported. For very large files, consider splitting them first for faster processing.