Text utilities

Remove Duplicate Lines

Remove duplicate lines from text locally with case-sensitive, trim, preserve-order, and sort options.

Runs locally in your browser
Drop a text fileRemoves duplicate lines locally. The file is not uploaded.
Input lines8
Unique lines3
Duplicates removed4
Empty lines removed1

How to use this tool

Paste text or drop a local text file into the tool.

Choose whether duplicate matching should be case-sensitive, whether lines should be trimmed before comparison, and whether empty lines should be removed.

Keep first-seen order for logs and lists, or disable it when you want alphabetically sorted unique lines.

When duplicate line removal helps

Removing duplicate lines is useful for cleaning keyword lists, URL lists, log samples, CSV-like exports, email lists, redirects, and configuration snippets.

It can make diffs easier to review and reduce noisy repeated values before importing data into another tool.

For structured data such as CSV, review the output before replacing the original file because duplicate rows can sometimes be meaningful.

Case-sensitive and trim behavior

Case-insensitive matching treats `Apple` and `apple` as the same line.

Trim-before-compare treats leading and trailing spaces as accidental whitespace and outputs the trimmed first unique value.

If spaces are meaningful, for example in code, fixed-width data, or indented text, disable trim before comparing.

Examples

Clean a keyword list

Input
tools
seo
Tools
privacy
seo
Output
tools
seo
privacy

Preserve log order

Keep first-seen order enabled when the sequence matters, such as in log lines, redirects, or manual review lists.

FAQ

Does this upload my text file?

No. Text files are read locally in your browser and the contents are not sent to Lumio.

What does case-sensitive matching mean?

When enabled, `Apple` and `apple` are treated as different lines. When disabled, they are treated as duplicates.

Should I trim lines before comparing?

Trim when leading and trailing spaces are accidental. Disable it when whitespace is meaningful, such as code or fixed-width data.

Can this safely clean CSV rows?

It can remove duplicate text rows, but it does not parse CSV columns. Review the output before using it as production data.