Remove Duplicate Lines
Remove repeated lines from a list while keeping the first occurrence. Control case, surrounding whitespace and blank lines, and inspect the duplicates separately.
About the Remove Duplicate Lines
Paste a list of names, URLs, IDs or email addresses to keep the first occurrence of each matching line. Matching ignores capitalization by default; enable Case Sensitive if Apple and apple should stay separate. Ignore edge whitespace when matching treats padded and unpadded entries as the same without rewriting the first original line. Remove blank lines is a separate option. The second output shows repeated entries so you can review what was removed before copying the cleaned list. This compares whole text lines, not the meaning of sentences or individual spreadsheet cells.
Features
- Keep first occurrences in original order
- Choose case-sensitive or case-insensitive matching
- Optionally ignore surrounding whitespace during matching
- Remove blank lines separately from duplicates
- Inspect the duplicate entries beside the cleaned list
- Copy or download the cleaned text without uploading it
How to use this tool
The Remove Duplicate Lines works right in your browser — no signup, no installation. Follow these steps:
- Paste the list into the input, with one item per line.
- Enable Case Sensitive if capitalization matters. Optionally ignore edge whitespace and remove blank lines.
- Review the cleaned list, repeated entries and removal counts.
- Copy or download the cleaned list.
Frequently asked questions
Does this preserve line order?
Yes. When a duplicate line is found, the first occurrence is kept in its original position and subsequent occurrences are removed. This preserves the original line order of your text.
What is the difference between case-sensitive and case-insensitive?
Case-sensitive means "Hello" and "hello" are treated as different lines and both will be kept. Case-insensitive means they are treated as the same line, so only the first occurrence is kept.
Can I deduplicate very large text?
Yes. Since all processing happens in your browser, the tool can handle large amounts of text. Performance depends on your device, but the deduplication algorithm is efficient for most practical use cases.
Using the results
Bulk text edits that would take ages by hand happen in one step with the Remove Duplicate Lines. It applies your changes the moment you make them, entirely in the browser, so your content stays on your device and the result is ready to copy immediately.