Your data never leaves your browser

Transform Your Data
in Seconds

Free online tools to merge, convert, and transform CSV & JSON files. No signup required. No data uploads. Just fast, private, instant processing.

Combine multiple CSV files into one. Perfect for merging exports from different sources.

Convert CSV files to JSON format instantly. Great for developers working with APIs.

Convert JSON data to CSV format for easy use in spreadsheets and databases.

Convert CSV to Excel (.xlsx) format for sharing and formatting.

Convert Excel files to CSV for easy data processing and sharing.

Find and remove duplicate rows from your CSV files automatically.

Why CSVTools.dev?

Built for people who work with data every day

All processing happens in your browser. Your files are never uploaded to any server.

Instant results powered by client-side processing. No waiting for server responses.

No signup, no paywalls for basic use. All tools are free for files up to 5MB.

Pro plan with 200MB file limit, unlimited processing, and batch operations — coming soon.

Get notified at launch