Clean a CSV locally without uploading it.
Open a CSV in your browser, inspect its quality, apply precise cleanup rules, and download a separate cleaned file. Your source stays on your device throughout the local workflow.
1. Choose a CSV to clean
Your file opens directly in the local app. Contents stay in this browser; no account needed.
Up to 20 MiB, 100,000 rows and 500 columns.
- Choose CSV
- Profile and choose cleanup rules
- Review and download a new CSV
Profile the file before changing it
See filled, empty, unique and repeated value counts for every column. The profile makes quality problems visible before a cleanup rule changes the preview.
Apply only the rules you choose
Trim or collapse whitespace, change text case, convert empty values to nulls, and deduplicate complete rows or selected key columns. Every rule appears in a visible plan that you can undo or reset.
Review uncertain matches separately
Fuzzy matching suggests similar values for human review. A suggestion never changes or deletes a record, because similar names are not proof that two business records are the same.
Work within clear local limits
Local mode accepts CSV files up to 20 MiB, 100,000 rows and 500 columns. The table previews up to 100 rows, while export processes the complete accepted file and creates a new CSV.
Frequently asked questions
What cleanup rules can I apply to a CSV?
Choose whitespace, text case, empty-value and exact-deduplication rules. Apply them in an ordered plan, inspect the preview and download a separate CSV.
Is my CSV uploaded when I clean it locally?
No. Local cleaning processes the CSV in this browser without an account. Temporary Loam mode is a separate option and uploads a copy only after you confirm it in the application.
Which files can I clean?
Local mode accepts one CSV up to 20 MiB, 100,000 rows and 500 columns. Export other formats as CSV first. Download your cleaned result before refreshing or closing the tab.
Does cleaning overwrite my original CSV?
No. Rules change a preview that you can undo or reset. Export downloads a separate cleaned CSV and processes the complete accepted file.