Remove Duplicate Lines
Delete repeated lines from any list, with options to trim whitespace, ignore case and sort.
Remove duplicate lines instantly
The Remove Duplicate Lines tool cleans up any list by deleting repeated lines while keeping the first occurrence of each. Options let you trim whitespace, ignore case, and sort the result alphabetically. Paste your text and get a clean, de-duplicated list — with a count of how many lines were removed — all in your browser.
When you need to dedupe
Duplicate lines creep into all kinds of data: email lists, keyword lists, log files, CSV columns, and anything copied together from multiple sources. Removing them by hand is tedious and error-prone. This tool does it instantly, which is invaluable before importing a list, running a mail merge, or analyzing data where duplicates would skew the results.
How to use it
- Paste your lines into the box.
- Choose options: trim whitespace, ignore case, or sort.
- Copy the de-duplicated result.
What the options do
| Option | Effect |
|---|---|
| Trim whitespace | Treats " apple " and "apple" as the same line |
| Case-insensitive | Treats "Apple" and "apple" as duplicates |
| Sort A→Z | Alphabetizes the unique lines |
Why options matter
Whether two lines are "duplicates" depends on context. Stray spaces from copy-pasting can hide duplicates, so trimming catches them. Email addresses and usernames are often case-insensitive, so ignoring case avoids keeping near-identical entries. Sorting makes the cleaned list easier to scan and compare. Toggle these to match exactly what "duplicate" means for your data.
Common uses
- Cleaning email or contact lists before sending.
- De-duplicating keyword lists for SEO.
- Tidying exported data and CSV columns.
- Removing repeated entries from logs.
Private and free
All processing happens in your browser — your list is never uploaded or stored. The tool is completely free with no limits.
Frequently asked questions
Does it keep the first or last occurrence?
It keeps the first occurrence of each line and removes any later duplicates.
Can it ignore case and whitespace?
Yes. Toggle case-insensitive to treat 'Apple' and 'apple' as the same, and trim to ignore surrounding spaces.
Can I sort the result?
Yes. Enable Sort A→Z to alphabetize the de-duplicated lines.
Is my data private?
Yes. Everything runs in your browser and nothing is uploaded or stored.