Trim whitespace, reformat fields, find and replace, apply regex, concatenate columns, add static values, and exclude unwanted columns. Live preview of every change. No uploads required.
All transformations run in your browser. Preview the first 5 rows before downloading your clean CSV.
Your CSV is processed entirely in your browser. We never see your data. No account required.
Click to browse or drag and drop
Configure transformations below. They run top to bottom in the order listed. Preview updates as you type.
Uncheck columns to exclude them from the output. New columns are highlighted in purple.
Next step
Need to split this clean CSV into smaller files?
Split by row count, file size, or column value.
Upload once, configure transformations, preview the result, and download a clean UTF-8 encoded CSV. Everything runs in your browser.
Click the upload zone or drag and drop your CSV file. Processed entirely in your browser using PapaParse. Nothing sent to a server.
Toggle global trim and randomise, add per-column operations (case, prefix, suffix, find/replace, regex), concatenate fields, or add static value columns.
A live table shows the first 5 rows with changes highlighted in purple. Changed cells update as you type. Exclude columns using the column picker.
Click Clean and Download. Your transformed file is UTF-8 encoded with a BOM for Excel compatibility, CRLF line endings, and only the selected columns.
Eight field operations plus global utilities. Stack as many as you need, in any order.
Remove leading and trailing spaces from every value in every column globally. The most common cause of mismatched records in joined datasets.
Apply UPPERCASE, lowercase, Title Case, or Sentence case to any column. Normalises contact names, region codes, and status values.
Prepend or append text to every value in a column. Useful for adding country codes, ID prefixes, or batch labels.
Exact string replacement across an entire column. Replace "N/A" with blank, fix known typos, or reformat date strings.
JavaScript regex find and replace with configurable flags (g, i, m). Use $1/$2 for capture groups. Invalid patterns leave values unchanged.
Combine two or more columns into a new column with a configurable separator. Classic use case: FirstName + LastName = FullName.
Add a new column with the same value in every row. Useful for tagging records with a BatchID, Wave, Region, or Status before import.
Choose exactly which columns appear in the output using the column picker. Uncheck any column to remove it. Works with original and new columns alike.
Common questions about cleaning and transforming CSV files online.
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