Remove Duplicate Lines
Paste your text below to remove duplicate lines instantly. The first occurrence of each line is kept; all subsequent duplicates are removed. Useful for cleaning up lists, log files, spreadsheet exports, and more.
How to Remove Duplicate Lines
- Paste your text into the Input box. This can be a list of names, email addresses, keywords, log entries, or any line-by-line content.
- Choose your options — enable case-insensitive matching to treat "Apple" and "apple" as the same; enable blank line removal to strip empty rows; enable line trimming to ignore leading and trailing spaces when comparing.
- Click Remove Duplicates — the result appears instantly in the Output box. The status line shows how many unique lines were kept and how many duplicates were removed.
- Copy or use the result — click Copy Result to copy the deduplicated text to your clipboard.
Common Uses
Cleaning Email Lists
Remove duplicate email addresses from a mailing list export. Use case-insensitive matching to catch duplicates that differ only in capitalisation (e.g. User@Example.com and user@example.com).
Deduplicating Keywords
When combining keyword lists from multiple sources, duplicates are common. Paste all keywords into the tool and get a clean unique set in seconds.
Cleaning Log Files
Remove repeated log entries or error messages when you only need to see unique lines. Great for trimming verbose logs to find distinct events.
Spreadsheet Data
Copy a column of values from a spreadsheet, paste it here to remove duplicates, then paste the unique values back. Faster than using spreadsheet formulas for a quick cleanup.
Frequently Asked Questions
Does the order of lines change?
No. Lines are kept in their original order. The first occurrence of each line is preserved; later duplicates are removed. The output is not sorted.
What does case-insensitive matching do?
With case-insensitive matching enabled, "Hello", "hello", and "HELLO" are treated as the same line and only the first occurrence is kept. The original capitalisation of the kept line is preserved.
What does "Trim whitespace" do?
When enabled, leading and trailing spaces are stripped from each line before comparison. So " apple " and "apple" are treated as duplicates. The trimmed version is written to the output.
Is there a limit on how much text I can paste?
No. The tool runs entirely in your browser and processes text locally — no data is sent to a server. Performance is limited only by your device, but it handles hundreds of thousands of lines without issue.
