Remove Duplicate Lines

Remove duplicate lines from a list, with options to ignore case, trim whitespace, and drop blank lines.

Cleaning up email lists, keyword lists, logs, and CSV columns.

How to use it

  1. Paste your list

    Add your list with one item per line.

  2. Set the options

    Choose whether to ignore case, trim whitespace, and remove blank lines so duplicates are caught reliably.

  3. Copy the unique lines

    See how many duplicates were removed, then copy the cleaned list.

Why use this tool?

Lists that come out of spreadsheets, logs, exports, or scraped pages are full of repeats, and duplicates cause real problems downstream — double-emailing the same contact, skewed keyword counts, or noise that hides the entries that actually matter. Spotting and deleting repeats by hand in a long list is slow and unreliable. This tool keeps only the unique lines in one click, and tells you how many duplicates it removed so you can see the effect. Paste your list (one item per line), and optionally ignore case, trim surrounding whitespace, and drop blank lines so near-identical entries are correctly treated as the same. It preserves the original order — keeping the first occurrence of each line — and runs entirely in your browser, so even large or sensitive lists never leave your device.

Common use cases

Email & contact lists

Strip repeated addresses before importing into a mailing or CRM tool.

Keyword research

De-duplicate keyword and tag lists for SEO and ad campaigns.

Log analysis

Collapse repeated log lines to surface the unique events.

Data cleanup

Tidy a column pasted from a spreadsheet before further processing.

Inventory & catalogues

Remove duplicate SKUs, tags, or entries from a combined list.

Frequently asked questions

Does it keep the original order?

Yes. The first occurrence of each line stays in its original position; later repeats are removed.

Can it ignore case and spaces?

Yes. Enable “ignore case” and “trim whitespace” so entries that differ only by capitalisation or padding are treated as duplicates.

Does it count how many it removed?

Yes — it reports the number of duplicates removed so you can confirm the result.

What counts as a duplicate?

An exact line match by default; with the options on, lines that match after trimming and case-folding also count.

Can it also remove blank lines?

Yes — toggle the remove-blank-lines option to drop empty lines as well.

Is there a size limit?

It handles large lists comfortably since everything runs locally in your browser.

Is my data uploaded?

No. The whole process happens in your browser, so nothing leaves your device.

Is it free?

Yes — de-duplicate lists of any length for free, with no sign-up.

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