UlvixorCSV Cleaner & Duplicate Remover
Clean up your CSV in seconds: trim stray whitespace from every cell and remove rows that are exact duplicates. It's an all-in-one CSV cleaner and duplicate remover that runs 100% locally in your browser.
How it works
- Paste your CSV into the input panel (or use the built-in example).
- The tool trims leading and trailing whitespace from every cell.
- It then finds and removes rows that are identical to one already seen.
- A summary shows the number of rows processed, duplicates removed, and cells trimmed.
- Copy the cleaned CSV or download it as a .csv file.
Use cases
- Remove duplicate rows from a contact or customer list exported from a CRM.
- Clean up stray spaces introduced when copying data from Excel or a form.
- Prepare a CSV for import into a database that rejects duplicate records.
- Standardize CSV files from different sources before merging them.
Use cases
- Remove duplicate rows from a contact or customer list exported from a CRM.
- Clean up stray spaces introduced when copying data from Excel or a form.
- Prepare a CSV for import into a database that rejects duplicate records.
- Standardize CSV files from different sources before merging them.
Common mistakes
- Expecting duplicates that only differ by letter case to be removed too.The comparison is exact after trimming spaces; "Ana" and "ana" aren't considered the same row. If you need to unify case first, use the Text Data Normalizer before removing duplicates.
- Thinking 'almost identical' rows with one different value in another column get removed.Only rows where every column matches exactly after trimming are removed. Partially different rows are kept as-is.
- Not checking the summary and assuming how many rows changed.The tool shows a summary with the exact number of duplicates removed and cells trimmed, so you can confirm what changed before downloading the result.
Frequently asked questions
No. The CSV cleanup happens entirely in your browser using JavaScript. Your file never leaves your device.
Two rows are considered duplicates when, after trimming whitespace from each cell, every column has exactly the same value. Only the first occurrence of each row is kept.
Whitespace trimming happens before rows are compared, so two rows that only differ by extra spaces (for example " Ana " and "Ana") are treated as duplicates.
No. The tool only trims leading and trailing whitespace from each value and removes repeated rows — it doesn't change letter case, numbers, or any other content.
Alternatives
In a spreadsheet, Excel and Google Sheets have a 'Remove duplicates' feature, and in the terminal awk '!seen[$0]++' does something similar line by line. This tool combines whitespace trimming and duplicate removal in a single step, with no program to open.