How to remove duplicate lines
Paste a list, exported column, log excerpt, or any text where each item is on its own line. The result updates immediately and keeps the first occurrence of each matching line.
Use Trim spaces before comparing when copied data has inconsistent leading or trailing spaces. Use Ignore case when Apple and apple should count as the same line. Use Remove empty lines when blank rows should not appear in the cleaned output.
What counts as a duplicate
By default, two lines must match exactly. That means extra spaces, different capitalization, and visually similar Unicode characters can still be treated as different lines. This exact behavior is useful when cleaning data where small differences matter.
When comparison options are enabled, the tool changes only how duplicates are detected. It does not rewrite the kept line, so the output preserves the first original version that matched.
Common uses
- Clean copied spreadsheet rows before pasting them back into a sheet.
- Remove repeated keywords, tags, IDs, email domains, or URL lists.
- Deduplicate log snippets while keeping the first occurrence in context.
- Count how many duplicate or empty lines were removed before sharing a list.
Privacy and limits
The text stays in your browser. MyTool0 does not upload the pasted content, store it, or send the cleaned result to analytics.
Very large text can still use browser memory because the tool compares each line locally. For everyday lists, CSV columns, keyword sets, and short logs, it should respond instantly.