Remove Duplicates
Remove duplicate lines from text
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
About this tool
Scans a list of text lines and removes exact duplicates, leaving only unique entries - useful for cleaning up mailing lists, deduplicating a list of URLs or emails, or tidying up any line-based data before using it elsewhere.
How to use this tool
- Paste line-based textInput emails, URLs, keywords, or any newline-separated data list.
- Choose matching behaviorSet case sensitivity and whitespace handling based on dataset quality.
- Run deduplicationKeep first unique occurrences and remove repeated lines automatically.
- Copy cleaned outputUse deduplicated list for campaigns, imports, or analysis pipelines.
Cleaning a mailing list or URL list
Before removing duplicates, trim stray spaces and make everything the same case, so "Ana@Example.com " and "ana@example.com" are treated as the same entry. Then paste the list and keep the first occurrence of each line.
For email lists, also check for typos such as gmial.com, and remove addresses that have bounced before.
Key features
- Quickly removes repeated entries from large text lists.
- Improves data quality before import or outreach tasks.
- Preserves useful order while cleaning duplicates.
- Useful for marketing, SEO, and operations datasets.
Common uses
- Cleaning duplicate email recipients before sending campaigns.
- Deduplicating URL inventories for SEO audits.
- Preparing unique keyword sets for ads/content research.
- Normalizing copied spreadsheet lines before upload.
Tips for better results
- Normalize case when matching user-generated email lists.
- Trim trailing spaces to avoid false “unique” duplicates.
- Review top and bottom output quickly for format drift.
- Keep original raw list archived before destructive cleanup.
Mistakes to avoid
- Treating near-matches as exact duplicates unintentionally.
- Ignoring case/whitespace settings for messy datasets.
- Assuming dedupe fixes invalid syntax or malformed entries.
- Overwriting source list without keeping a backup copy.
Frequently asked questions
This depends on whether case-sensitive matching is enabled - check the tool's settings if you need "Example" and "example" treated as duplicates or as distinct lines.
Typically yes - unique lines are kept in their original order, with only the duplicate repeats removed, rather than being resorted alphabetically.
The whole line's text is compared - two lines must match completely (aside from case settings) to be treated as duplicates.
Lowercase the addresses and trim spaces first, because Name@Example.com and name@example.com are the same mailbox. Then remove duplicates; that keeps people from receiving the same email twice.
Invisible differences such as a trailing space, a tab or a different line ending make lines unequal. Trim whitespace before deduplicating if lines that look identical survive.
Copy the column, paste it here, deduplicate and paste the result back. For whole rows with several columns, Excel's Remove Duplicates or Google Sheets' Data > Data cleanup are the better fit.