Remove Duplicate Lines
Deduplicate lists, keep first occurrences
Duplicate removal here is stable, which is the part that matters. The first time a line appears it is kept, and every later copy is dropped, so the surviving order is exactly the order you pasted. Comparison is made on the trimmed version of each line, so a value with trailing spaces from a spreadsheet is recognised as the same as a clean one, while the copy that survives is the original with its own spacing intact. An ignore-case switch extends the same idea to capitalisation, turning Ada, ada and ADA into a single entry. The result is the deduplicated list and nothing else — there is no count of removals, no sorting and no report of what changed, so if you need a diff of what went, compare the two texts elsewhere. Text is processed locally in the browser.
Remove duplicate lines from any list with case-sensitive or insensitive matching. The fastest way to clean email lists, keyword exports, log files and any repeating data.
Private Remove Duplicate Lines In Your Browser
Remove Duplicate Lines is processed locally with client-side JavaScript. Your files never touch a server, and there is no queue to wait in.
How to use Remove Duplicate Lines
Paste your list into the Input box, one entry per line.
Tick Ignore case if entries that differ only in capitalisation should count as the same.
Read the deduplicated list in the Result panel, in the original order.
Copy the result, or switch the operation to sorting if you also need the list ordered.
- First occurrence is kept, so the output preserves your original ordering
- Comparison ignores surrounding whitespace on each line
- Optional case-insensitive matching for entries that differ only in capitals
- Runs entirely in the browser on the pasted text
- A marketer cleaning an email export where the same contact was exported twice.
- A developer reducing a keyword list to unique values before importing them.
- A log analyst collapsing thousands of repeated lines in a captured session trace.