Remove Duplicate Lines
Delete repeated lines.
Remove Duplicate Lines at a glance
Remove Duplicate Lines is a free online text tool you can use right now to delete repeated lines โ no account, no install and no usage limit. It runs entirely inside your browser, so whatever you enter stays on your own device.
- Price
- Free โ no trial, no paid tier, no watermark
- Sign-up
- Not required
- Where it runs
- In your browser โ nothing is uploaded to a server
- Works on
- Chrome, Safari, Firefox and Edge โ desktop, tablet and phone
- Category
- Text Tools
About Remove Duplicate Lines
Paste a list and remove repeated lines, keeping the first occurrence of each.
The most common frustration is duplicates that are not removed because they are not actually identical. Trailing whitespace is invisible and makes two lines different to a computer that look the same to you. So does a capital letter, and so does a carriage return left behind by a Windows-style line ending on a file processed with Unix tools. Trimming whitespace and matching case-insensitively resolves nearly all of these.
Deduplication is not the same as sorting, though the two are often confused. Removing duplicates here preserves the original order, keeping the first instance of each line. Some command-line workflows require sorted input to deduplicate, which reorders everything as a side effect โ that is a limitation of those tools rather than a property of the operation.
Useful for cleaning exported email lists, consolidating log lines, merging several lists into one, or preparing data before an import that will reject duplicate keys.
How to use Remove Duplicate Lines
- Paste your list, one item per line.
- Choose whether to ignore case and trim whitespace.
- Copy the deduplicated result, which keeps the original order.
Frequently asked questions
Why were my duplicates not removed?
Almost always invisible differences โ trailing whitespace, inconsistent capitalisation, or a stray carriage return from a Windows line ending. Enable trimming and case-insensitive matching to catch these.
Does this sort my list?
No. Original order is preserved and the first occurrence of each line is kept. Sorting is a separate operation.
Which duplicate is kept?
The first occurrence. Later repeats are removed, so the earliest position in your list is what survives.
Is there a size limit?
No fixed limit โ processing happens in your browser, so the practical ceiling is available memory. Lists of many thousands of lines are handled without difficulty.