Compare Two Lists
Find values that appear in both lists, only in the first list or only in the second list after safe normalization.
Cleanup
Remove Duplicate Lines from a List
Remove repeated lines while preserving the first occurrence and the original readable capitalization of each unique value.
Processing boundary: text and files are handled only for this request. Original files are not overwritten. Generated CSV downloads use expiring private tokens.
What this tool does
Repeated values often enter spreadsheets through copy-and-paste, appended reports or inconsistent exports. This utility removes duplicates from a one-value-per-line list while retaining the first occurrence and the original order. Matching ignores case and normalizes surrounding whitespace so values that differ only by accidental spacing are not counted twice. It is suited to small preparation tasks before a lookup, import or reconciliation, and the cleaned list remains visible for review before you copy it.
How to use it
- Paste one value per line.
- Run the cleanup.
- Review the input, unique and removed counts, then copy the cleaned result.
Limitations and review points
Values are treated as duplicates only after text normalization. The tool does not merge similar names, correct spelling or decide whether two different codes belong to the same entity.
Frequently asked questions
Does it preserve order?
Yes. The first occurrence stays in its original position.
Does it remove blank lines?
Yes. Blank-only lines are omitted.
Will John Smith and Jon Smith be merged?
No. Fuzzy matching is not used in this cleanup tool.
Related spreadsheet tools
Spreadsheet Data Quality Checker
Measure blanks, outer whitespace, repeated values and case inconsistencies that can interfere with matching and reporting.
Find Duplicate Rows
Find every repeated key in a CSV, TSV or XLSX file and export the affected rows for review or correction.