Free Remove Duplicate Lines
Paste a list and remove duplicate lines (optionally ignoring case) and empty lines — handy for cleaning up emails, keywords or any line-by-line list.
What is the remove duplicate lines?
A remove duplicate lines tool is a free utility that deletes repeated lines from a list so each entry appears only once. You paste a list — emails, keywords, URLs or any line-by-line data — and it keeps the first occurrence of every line and removes the rest. Slashit's tool runs in your browser, so your list stays private, and it can optionally ignore case when comparing lines or strip out empty lines at the same time. It's a fast way to de-duplicate and tidy a list without a spreadsheet.
How our free remove duplicate lines works
Paste your list
Add a list with one item per line — email addresses, keywords, URLs or any repeated data.
Remove the duplicates
Keep the first of each line and drop the rest. Optionally ignore case, or remove empty lines too.
Copy the clean list
The de-duplicated list appears instantly — copy it and use it wherever you need a clean set.
What can you use the remove duplicate lines for?
Deduplicating an email or contact list
Lists merged from several sources almost always contain repeats. Removing them prevents sending the same message to someone twice.
Cleaning up a keyword list
SEO keyword research from multiple tools produces heavy overlap, and duplicates distort the counts you're working from.
Tidying log or export data
Exports frequently repeat rows. Stripping duplicates makes the data easier to scan before analysis.
Consolidating notes and to-do lists
Combining several lists into one usually leaves the same item written more than once.
Who uses our free remove duplicate lines?
Marketers & SEO teams
De-duplicate keyword and URL lists so reports and campaigns don't double-count entries.
Data & ops teams
Clean exported lists of emails, IDs or records before importing them somewhere else.
Anyone with a list
Tidy any line-by-line list without opening a spreadsheet or writing a formula.
Why use the remove duplicate lines?
Instant de-duplication
Remove every repeat in one click while keeping the original order of the first occurrences.
Case-insensitive option
Treat lines that differ only in capitalisation as duplicates when you need to.
Free and private
No sign-up, and your list never leaves your browser.
Tips for getting the best results
Check whether case matters
“Apple” and “apple” may or may not be the same thing depending on your data. Normalise the case first if they should be treated as one.
Watch for trailing spaces
Two lines that look identical won't match if one ends in a space. Trimming whitespace first catches far more duplicates.
Keep a copy of the original
Deduplication is destructive. Keep the full list until you've confirmed the cleaned version is what you expected.
Near-duplicates still slip through
Only exact matches are removed, so “john@x.com” and “John@X.com ” with different spacing won't both go unless you normalise first.
Frequently asked questions
Does it keep the original order?
Yes. It keeps the first time each line appears and removes later duplicates, so the remaining lines stay in their original order.
Can it ignore capitalisation?
Yes. Turn on the ignore-case option to treat lines that differ only in letter case as duplicates.
Is it free?
Yes — it's free, needs no sign-up, and runs entirely in your browser.
How do I remove duplicate lines from a list?
Paste your list with one item per line. Repeated lines are removed and the first occurrence of each unique line is kept, in its original order.
Does it keep the original order?
Yes. The first time each line appears it's kept in place, so the sequence of your list is preserved.
Is the comparison case-sensitive?
Lines are matched exactly, so differences in capitalisation or spacing count as different lines. Normalise your text first if those should be treated as duplicates.
Is there a limit on list size?
No fixed limit — processing happens in your browser, so it handles large lists as fast as your device allows.
