Duplicate Line Finder
Find repeated entries in a pasted list and see how often each one occurs. Choose whether differently capitalised entries should match.
How to use Duplicate Line Finder
1. Paste or type your text or list into the box. 2. Choose any options shown, then select Find. 3. Select Copy result to copy the answer. 4. Select Reset to clear the box and start again.
Why use this tool?
Find duplicate rows before you clean a list or investigate an unexpected count. The tool shows the repeated values so you can decide which entries to keep.
How the calculation works
List normalised line keys that occur more than once, with their occurrence count. Entries are non-empty trimmed lines. Blank lines are ignored; repeated entries remain separate row slots unless the tool explicitly removes duplicates. Commas inside a line are retained. Case sensitivity is selected. Display preserves the last spelling seen for a repeated key; this does not identify files or people.
Example
Worked example: Lines = "A\na\nB"; Case Sensitive = false. Result: a — 2.
Practical tip
For names or identifiers, choose case-sensitive comparison if capital letters have meaning.
Frequently asked questions
How is a repeated entry displayed?
The result shows each matching value with its total occurrence count. If matching is not case-sensitive, the displayed spelling is the last version found.
Does this compare files or identify duplicate people?
No. It compares text entries, one per line. Matching names do not prove that two records describe the same person or file.
How do I copy the result or start again?
Select Copy result after running the tool to copy the displayed answer. Reset clears the text and result, so keep a separate copy of any text you want to save.