Remove Duplicate Lines
Paste any list and instantly remove duplicate entries with smart options — case control, trimming, sorting, and more.
Instant deduplication
Sort & shuffle
File upload
Download result
Paste Your Lines
Comparison
Cleanup
Sort Output
Line endings:
About Remove Duplicate Lines
The Remove Duplicate Lines tool is a free online utility that removes repeated lines from any text or list, keeping only the first occurrence of each unique line. It is a simple but essential tool for data cleaning, list management and content processing tasks.
Duplicate lines are common in exported data, copied lists, merged files and web scraping outputs. Cleaning them manually is tedious and error-prone — this tool handles thousands of lines in milliseconds.
How to Remove Duplicate Lines
- Paste your text or list into the input field
- Choose options: case-sensitive or case-insensitive matching; keep order or sort alphabetically
- Click Remove Duplicates
- Copy the clean list from the output field
- See how many duplicates were removed
Options Available
- Case sensitive — "Apple" and "apple" treated as different lines
- Case insensitive — "Apple" and "apple" treated as duplicates
- Trim whitespace — removes leading/trailing spaces before comparing
- Sort output — alphabetically sorts the de-duplicated list
Common Use Cases
- Cleaning email lists before import to your CRM
- De-duplicating keyword lists for SEO research
- Processing web scraping output
- Merging multiple data files and removing repeated entries
Free, unlimited line count, no login required.
Frequently Asked Questions
What does "case sensitive" mean?
With case sensitivity on, "Apple" and "apple" are treated as different entries and both kept. With it off (the default), they are considered duplicates and the second occurrence is removed. Most deduplication tasks are better with case sensitivity disabled.
What does "trim whitespace" do?
Trimming removes leading and trailing spaces from each line before comparing. So " apple " and "apple" would be treated as the same line and one is removed. This is helpful when your data comes from different sources with inconsistent spacing.
Can I sort the output?
Yes — use the Sort Output dropdown to order results A→Z, Z→A, by line length, or randomly. Sorting happens after deduplication so your final list is clean and ordered in one step.
What is the file size limit for upload?
The tool works entirely in your browser, so the practical limit is your browser's memory. For very large files (100k+ lines), the tool may take a few seconds to process — this is normal and all processing stays on your device, not sent to any server.
How do I download the result?
Type a filename in the download field and click "Download .txt". Choose Unix line endings (LF) for Mac/Linux files, or Windows (CRLF) for Windows compatibility. The file downloads directly to your computer.