🗑️ Remove Duplicate Lines
Remove duplicate lines from your text with flexible case and trimming options — all in your browser, no upload, instant results.
About the Remove Duplicate Lines tool
This tool runs entirely in your browser. Paste a list of lines, choose how duplicates should be detected and which occurrence to keep, then click Process. Nothing is uploaded to a server — the deduplication happens locally with JavaScript on your device.
Options explained
- Case sensitive — When checked,
Appleandappleare treated as different lines. When unchecked, they are considered duplicates. - Trim whitespace before comparing — When checked, leading and trailing whitespace is ignored when comparing lines, so
" hello "matches"hello". The original text is preserved in the output. - Keep first occurrence — Keeps the first time a line appears and removes later duplicates.
- Keep last occurrence — Keeps the last time a line appears and removes earlier duplicates.
- Remove all duplicates — Removes every line that appears more than once, leaving only lines that were unique in the input.
How to use the tool
- Paste your text into the input box.
- Configure the case sensitivity, trimming, and keep options.
- Click Process — the deduplicated result appears in the output box, with stats showing how many lines were removed.
- Click Copy result to copy the output to your clipboard, or Clear to start over.
Frequently asked questions
Does this tool upload my text? No. All processing happens locally in your browser. Your text never leaves your device.
Does it preserve the original line order? Yes. The tool keeps lines in their original order, only removing the duplicates based on your chosen strategy.
What counts as a line? Lines are separated by line breaks. Both LF (\n) and CRLF (\r\n) are handled correctly.
Is there a length limit? The only limit is your browser's available memory. Even very long lists deduplicate instantly.