CyberCodeRemove Duplicate Lines
Free online tool to remove duplicate lines from text. Paste a list, click once and get every line only once — with optional case-sensitive matching. Runs 100% in your browser.
When do you need to remove duplicate lines?
Duplicate lines creep into every merged list: email lists combined from two exports, keyword lists from multiple research tools, log files, inventory sheets. Removing them by hand is error-prone above a few dozen lines.
This tool keeps the first occurrence of each line and preserves the original order — the behaviour you almost always want, unlike sorting-based deduplication which scrambles your list. Case-sensitive matching is optional.
How to use
- 01Paste your list or text into the input box.
- 02Choose whether matching should be case sensitive and whether to trim whitespace first.
- 03Click Remove duplicates — the first occurrence of each line is kept.
- 04Copy or download the deduplicated result.
Frequently asked questions
- Which duplicate is kept — the first or the last?
- The first occurrence of each line is kept and all later duplicates are removed, so the original order of your list is preserved.
- What does the case sensitive option do?
- With case sensitivity on, 'Apple' and 'apple' are treated as different lines. Turn it off to treat them as duplicates of each other.
- Is my list uploaded anywhere?
- No. Deduplication runs entirely in your browser with JavaScript — your data never leaves your device.