LazyTools

🔒 Every tool runs in your browser — the files and values you enter are never uploaded to any server. How it works

🧹 Remove Duplicate Lines

Paste a list, get it back with duplicates removed — first occurrence kept, order preserved.

1 duplicate line removed

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How the remove duplicate lines works

Each line is compared against every line seen before it; repeats are dropped and the first occurrence kept, so your original order survives. "Ignore case" treats Apple and apple as the same line; "ignore spaces" disregards invisible leading/trailing whitespace — the most common reason two identical-looking lines both survive.

Typical jobs: cleaning email lists, keyword lists, log extracts and spreadsheet columns pasted as text. For a sorted unique list, run this tool first, then the sort-lines tool — or vice versa; the result is the same set.

Frequently asked questions

Does it keep the first or last occurrence?

The first — everything after a line’s first appearance is removed, and the surviving lines keep their original order.

Why do two identical-looking lines both remain?

Almost always invisible trailing spaces or different capitalization. Enable both options and they will merge.

Can I deduplicate comma-separated values?

Put each value on its own line first — the find & replace tool converts ", " to line breaks in one step — then dedupe.

Is there a size limit?

Practically no — tens of thousands of lines process instantly, since everything runs locally in your browser.

Is my list uploaded anywhere?

No. Lists often contain emails or customer data — exactly why this tool never transmits anything.

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