CleanMySheet guide
Clean a CSV online without uploading it
CleanMySheet cleans CSV files entirely in your browser. Drop a file, review a scan of issues, apply presets (trim, dates, duplicates, names, phones), then export. Strict mode is on by default so column samples never leave the device.
Open the cleanerSteps
- Drop a .csv file or try the sample dataset
- Read the scan: duplicates, dates, phones, empties
- Apply recommended presets or search for a fix
- Preview Original, Cleaned, and Diff
- Download CSV (free up to 500 rows) plus a recipe and quality report
What “clean CSV” actually means
A messy CSV usually has extra spaces, mixed date formats (03/14/22 vs March 14 2022), duplicate contacts, N/A placeholders, and names in Last, First order. Cleaning is applying reversible, named operations—not asking a chatbot to rewrite your rows. CleanMySheet records why each cell changed.
Why not paste the file into ChatGPT?
Large language models can invent values, drop rows, or reformat columns inconsistently. They also require you to send data to a server. CleanMySheet uses deterministic rules first (dates, numbers, trim, dedup). Optional AI classification sends only column samples, and only if you turn Strict mode off.
CSV vs Excel
The same engine parses CSV (PapaParse) and Excel/XLSX (SheetJS), including Excel serial dates and multiple sheets. If you have an .xlsx, use the clean Excel workflow; the recipe still exports as CSV for the MVP.
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