CSV ↔ JSON Converter
Convert CSV and JSON locally while preserving IDs and validating columns.
Free, local processing. Files and cell values are never sent to our server. Limit: 2 MB per file, 2 million input characters, 10,000 data rows and 200 columns.
CSV needs unique, non-empty headers and matching row widths. Cell values stay strings, preserving leading zeros and long IDs. JSON input must be an array of flat objects; missing values and null become empty CSV cells. Use strings for large numeric IDs. Safe export changes formula-like cells; turn it off only when exact values are required and you trust the input.
Need to remove duplicate rows? Open CSV Cleaner →Save this page in your browser bookmarks to use it again.
About this tool
Move tabular data between spreadsheets and integrations with explicit validation. CSV cell values remain strings, including leading-zero IDs. JSON-to-CSV supports flat objects and an optional spreadsheet-safe export.
Frequently asked questions
What does CSV ↔ JSON Converter do?
Convert CSV and JSON locally while preserving IDs and validating columns.
Do I need an account?
No. This free tool can be used without creating an account.
Where is my input processed?
This tool processes its input in your browser. Tool input is not uploaded for processing. General site usage statistics are separate; see the privacy policy.