Remove Duplicate Lines
Clean repeated entries from a list with one item per line. Decide whether case or surrounding whitespace should affect matching, then review the remaining lines before using them.
Before you start
- Input
- A plain-text list with one entry per line.
- Output
- A list preserving the first matching occurrence.
Loading tool…
How to use this tool
- Paste a list with one item per line.
- Choose case, whitespace and blank-line options.
- Review the number of removed lines and copy the result.
Understand the result
Exact matching treats Apple and apple as different entries. Case-insensitive matching can treat them as duplicates. The trim-for-matching option ignores surrounding whitespace during comparison while retaining the first matching line's original text in the output.
How do I remove duplicate lines while keeping the original order?
Paste a list with one item per line and generate the result. The first matching occurrence is kept and later matches are removed. For Apple, Banana and Apple on separate lines, the result is Apple followed by Banana. Sorting is not applied, and the spelling and spaces of the retained line stay unchanged.
Why are two similar lines still in my list?
By default, matching is case-sensitive and surrounding spaces matter. Enable Ignore letter case for Apple and apple to match; enable the spacing option to ignore spaces at the start and end when matching. Choose whether to keep, remove or keep only the first blank line. The tool does not compare individual CSV columns or decide whether different names refer to the same item.
Try a sample
Try a sample with the tool above, then inspect the output before using your own files.
sample-list.txt ↓If the result is not what you expected
Two similar names were not merged.
Matching is based on lines and the selected spacing/case rules. It does not infer that two different spellings are the same person or parse CSV columns. Check the result before replacing a source list.
Next useful tool: Text Compare →Important limits
- Matches complete lines rather than similar names or database records. CSV columns are not parsed.
- Maximum 100,000 characters. Review the spacing and case options before replacing the original list.
Frequently asked questions
Will my list be sorted?
No. The first-release behavior preserves the order of the first occurrence of each retained line.
Are blank lines duplicates?
Blank-line handling is a separate option. Choose whether to preserve, reduce or remove blank lines before processing.
Questions or a correction? mrkcal@mrkcal.com