Remove Duplicate Lines
Remove Duplicate Lines
Deduplicate large text lists for logs, IDs, and copied datasets with sorting and normalization controls.
Live
3 unique line(s) from 5 considered entries. Removed 2 duplicate(s).
File input
Choose a file
Click, drop, or paste from clipboard.
Result
3 unique lines
Removed 2 duplicate line(s) • 40% duplicate rate.
Input lines
6
Considered lines
5
Removed duplicates
2
Skipped empty
1
Input: manual
Your input is processed locally in your browser whenever possible. We do not store your data.
Formula
Unique lines = preserve first line for each normalized key - Split input into line list preserving order.
- Normalize each line by selected case and trim options.
- Keep first unseen key and discard subsequent duplicates.
Example
Worked example: repeated values list
- 1 Input lines include repeated apple and banana entries.
- 2 Run dedupe with case-insensitive matching.
- 3 Output preserves first unique lines only.
Duplicate lines are removed while order stays stable.
How
- Paste multiline text in the input box.
- Set case sensitivity and whitespace options.
- Copy deduplicated output lines.
Cases
- Clean repeated IDs from spreadsheet exports.
- Prepare unique keyword sets for SEO analysis.
- Remove duplicate entries from copied logs.
Avoid
- Turning on trim option and expecting original spacing to remain unchanged.
- Forgetting to disable case sensitivity when deduping mixed-case lists.
- Assuming empty lines are preserved when keep-empty option is off.
FAQ
Can I keep empty lines in output?
Yes, enable keep empty lines option to preserve blank rows.
Is line order preserved after dedupe?
Yes, the first occurrence order is preserved in output.
Does this support case-insensitive mode?
Yes, case sensitivity can be toggled in options.
Switch
Switch12
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