Remove Duplicate Lines
Remove duplicate lines and delete repeated lines from a list, with case-insensitive matching, whitespace trimming, keep first or last, and optional sorting.
ToolsSoup's Remove Duplicate Lines tool is a free online deduplicator that deletes repeated lines from any list or block of text in one click. Paste your lines, choose whether matching should ignore case or surrounding whitespace, keep the first or the last copy of each line, and optionally sort the result alphabetically. You also get a summary of how many lines were kept and how many duplicates were removed. Everything runs in your browser — no uploads, no sign-up, and your text never leaves your device.
What does removing duplicate lines mean?
Removing duplicate lines means keeping only one copy of each line that appears more than once, so a list with repeated entries becomes a clean list of unique lines. This is handy for cleaning up email lists, keyword lists, log files, CSV columns, SQL output, and any text where the same value shows up again and again. Unlike a quick dedupe button buried in a counter, this dedicated tool gives you real control: match lines exactly or loosely, decide which copy to keep, and reorder the result, then copy the cleaned list.
How to remove duplicate lines online
Deleting repeated lines with ToolsSoup takes just a few seconds:
- Type directly into the text box or paste the list you want to clean.
- Set the options — ignore case, ignore leading and trailing whitespace, keep blank lines, keep the first or last copy, and optionally sort the result.
- Click Remove duplicates, check the kept and removed counts, then click Copy result to grab your clean list.
How duplicate detection works
Two lines are treated as duplicates when their comparison keys match. By default the comparison is exact: the lines must be character-for-character identical. Turn on Ignore case to treat upper and lower case as the same, and turn on Ignore leading and trailing whitespace to match lines that differ only by surrounding spaces or tabs. Keep first occurrence preserves the earliest copy of each line in its original position, while Keep last occurrence preserves the final copy instead. Keep blank lines leaves empty rows untouched so spacing is preserved, and Sort the result orders the surviving lines alphabetically.
Remove duplicate lines vs. count lines
A line counter tells you how many unique lines exist; this tool actually produces the deduplicated text. If you only need a number, a counter is enough — but when you need the clean list itself, with control over case sensitivity, whitespace, which copy survives, and ordering, a dedicated remove-duplicate-lines tool is the right fit. The kept and removed counts give you a quick before-and-after summary of exactly how much was trimmed.
Why use this remove duplicate lines tool?
- Delete repeated lines from any list in one click, with a clean deduped result.
- Optional case-insensitive matching and whitespace trimming for looser comparisons.
- Choose to keep the first or the last occurrence of each duplicate line.
- Optionally sort the result and keep blank lines to preserve spacing.
- See how many lines were kept and how many duplicates were removed.
- Runs entirely in your browser — your text is never uploaded, and the result copies in one click.
Frequently asked questions
How do I remove duplicate lines from my text?
Paste your list into the box, choose your matching options, and click Remove duplicates. The tool keeps one copy of each line, shows how many duplicates it removed, and puts the clean list in the result box ready to copy.
Can I ignore case when finding duplicates?
Yes. Turn on Ignore case and lines that differ only in capitalization, such as Apple and apple, are treated as the same line so only one copy is kept.
Does it keep the first or the last copy of a line?
You choose. Keep first occurrence preserves the earliest copy of each line in its original order, and Keep last occurrence preserves the final copy instead. Both remove every other repeat.
Can it ignore extra spaces around lines?
Yes. Turn on Ignore leading and trailing whitespace and the tool compares lines after trimming surrounding spaces and tabs, so lines that differ only by padding are counted as duplicates.
Will it remove blank lines too?
Only if you want it to. By default blank lines are deduplicated like any other line. Turn on Keep blank lines to leave every empty row in place so your spacing is preserved.
Is my text private?
Absolutely. All deduplication happens locally in your browser using JavaScript, so the text you enter is never sent to or stored on any server.