CSV to Excel
Convert a CSV file to Excel (.xlsx) in your browser. Download a real spreadsheet — nothing is uploaded.
CSV validator
Check a CSV for uneven columns and quoting errors in your browser. Review issues before using the file.
Drop a CSV file here or click to choose
Validated locally — nothing is uploaded
How to use CSV validator
Validate a CSV for malformed rows and bad quoting. Review issues before you use the file elsewhere.
Everything runs locally in your browser — your files are never uploaded to a server.
CSV validator FAQs
How do I validate a CSV file?
Drop a CSV to check for uneven field counts and parse or quoting errors. Issues are listed locally in your browser.
Is the CSV validator free?
Yes. Every Excel and CSV tool on ReallyUseful.Tools is free to use, with no account or subscription required.
Are my files uploaded?
No. Files are processed in your browser on this device. Nothing is uploaded to our servers.
What problems does it catch?
It flags empty files, rows with the wrong number of fields, and Papa Parse errors such as bad quoting.
More Excel/CSV
Excel to CSV
Convert Excel .xlsx or .xls to CSV in your browser. Choose a sheet and delimiter, then download.
CSV viewer
Open and browse a CSV in a paginated table in your browser. No upload — view large files locally.
Merge CSV files
Combine multiple CSV files into one in your browser. Rows are stacked and headers aligned by name.
CSV to XML
Convert CSV rows into structured XML in your browser. Each row becomes an element — nothing is uploaded.