Find CSV data quality problems before they spread.
Profile a CSV, identify inconsistent values and duplicates, then test focused cleanup rules against a live preview. The tool shows the evidence and leaves the final decision with you.
1. Choose a CSV to profile
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
- Inspect missing, unique and repeated values
- Choose any cleanup rules, review and download a new CSV
Measure before you modify
Filled, empty, unique and repeated value counts provide a baseline for each column. Value-length ranges can also reveal truncated identifiers or unexpected formatting.
Standardise predictable differences
Whitespace, case and empty-value rules address common inconsistencies. Apply them only to the columns you select, then compare the updated profile with the original condition.
Separate duplicates from possible matches
Exact-row and selected-key rules are deterministic. Fuzzy similarity is shown only as a review aid, so a weak match can never silently remove a business record.
Keep a clear review trail
The ordered plan records how the preview was produced. You can undo or reset it, and export always creates a separate cleaned file rather than changing the source.
Frequently asked questions
How can I check whether cleanup improved data quality?
Compare filled, empty, unique and repeated counts before and after each rule. Inspect the row preview before exporting, and undo or reset a rule if its result is unsuitable.
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.