01
Choose what makes a duplicate
Use an order ID, contact ID or a combination of columns. With no key selected, every column must match. Blank selected keys are retained and flagged for review.
Remove duplicates. Keep a record of what changed.
Clean CSV, TSV and XLSX exports in your browser. Choose full-row matching or select the columns that identify a duplicate, then keep the first occurrence and review removed rows separately.
File contents stay in your browserFree · no account to run or export
A PRACTICAL EXAMPLE
Two identical order rows with ID 00103 become one retained row and one entry in Removed rows. A different order with no ID is retained for review.
02
Fix only the columns you select
Trim whitespace across the table. Select specific columns for lowercase, dates or numbers. Choose day-first or month-first dates explicitly; identifiers remain text unless you select them for number formatting.
03
Review and download
The workbook includes cleaned data, a change report and removed rows. Unrecognised dates and numbers remain unchanged and are flagged. Reuse the same rules by saving a workflow.
Know what to expect
Duplicate removal keeps the first matching row. It does not decide which conflicting customer or order record is correct.
Supports CSV, TSV and unencrypted XLSX, up to 20 MB per file and 100 input columns. Free use includes 2,000 total input rows per run. Excel downloads contain text cells to preserve identifiers such as 00123. Workbook styling and formulas are not retained.
Read the file and export guideCompare Excel & CSV files by ID
Match records using an ID, even when rows move. See added, removed, changed and ambiguous records with their source-row references.
Merge CSV & Excel files online
Stack exports with different headers or join two files using an ID. Keep source file and row details so the combined result is easier to trace.
Map & rename CSV columns
Rename, reorder and select columns for an import. Set defaults or constant values, then save the mapping for the next export.