Cleaner CSV files. Clearer decisions.

CommaMend is a free CSV checking and repair website from Klauzi. It helps people understand broken rows, quotation errors, repeated headers, and other common problems before importing a file into another system.

One file, one clear next step

Select a CSV and the scan starts automatically. The results show real parsed records, physical line numbers, logical record numbers, and the affected columns. Review one issue at a time, preview a repair, approve it, and download your working copy.

Processing stays on your device

The CSV engine runs in your browser. There is no account, database, or file upload endpoint. A background worker handles the initial scan, and the preview uses pages to keep large tables manageable. The original file on your device is unchanged.

Repairs follow your instructions

An extra field does not reveal which values belong together. CommaMend asks you to choose the adjacent fields to combine. Empty and repeated records are removed only when approved. Text values, Unicode characters, leading zeros, and record order are preserved unless you approve a change.

Know the limits

The checker validates CSV structure. It does not certify compliance with a school, store, accounting system, or other importer’s business rules. Encoding detection can be uncertain, and an unclosed quote can hide the intended record boundaries. Check the preview and the receiving system’s import instructions. Files are limited to 20 MB, 150,000 records, 500 fields per record, and 1,000,000 cells.

Questions or a reproducible problem?

Contact us with a small, anonymized example and the expected result. Never send student records, passwords, payment information, or other sensitive data. Read the privacy notice for details.