Remove duplicate lines
Paste a list with repeated entries and strip duplicates in one step. Keep the first occurrence of each line or sort alphabetically after deduplication. Ideal for cleaning exported emails, server logs, tag lists, and inventory SKUs. Processing stays local — nothing is uploaded.
Input text
How to remove duplicate lines
1. Paste your text — one item per line.
2. Choose whether to preserve original order or sort lines after removing duplicates.
3. Optionally ignore case so "Apple" and "apple" count as the same line.
4. Copy the cleaned output.
Deduplication examples
Email list cleanup
A mailing list export with 1,200 lines may contain 340 duplicates. After deduping, 860 unique addresses remain in first-seen order.
Server log unique IPs
Paste 5,000 log lines and keep unique IP addresses one per line — faster than sort | uniq in a terminal for a quick check.
Tag list for a blog
"seo, marketing, SEO, content, marketing" split by line → unique tags: seo, marketing, content (case-insensitive option merges SEO and seo).
When to use duplicate line removal
• When you merge CSV exports and need unique values in one column.
• When you clean up pasted lists before importing into a CRM or spreadsheet.
• When you want unique entries from command output without opening a terminal.
When to choose something else
• When duplicates span multiple columns and rows — use spreadsheet software or a CSV tool.
• When you need fuzzy matching ("Jon Smith" vs "John Smith") — this tool matches exact lines only.
• When you need to compare two full documents — use the text diff tool.
Exact match vs fuzzy deduplication
This tool removes lines that are character-for-character identical (after optional case normalization). It will not merge "New York" and "New York, NY" or emails that differ by a dot in Gmail. For contact deduping, normalize formats first — trim spaces, lowercase emails, remove trailing punctuation — then run deduplication.
Order preservation in data pipelines
Keeping first-seen order matters when the list reflects priority or chronology — e.g. signup order or ranked keywords. Sorting after dedup is better when you need an alphabetical index of unique categories. Choose the mode before copying output into downstream tools.
Frequently asked questions
Does it remove empty lines?
Empty lines can be treated as duplicates of each other. Enable trim options if your tool supports stripping blank lines entirely.
Is comparison case-sensitive by default?
You can usually toggle case sensitivity. Case-insensitive mode treats "Error" and "error" as the same line.
Which duplicate is kept?
When preserving order, the first occurrence of each unique line is kept; later copies are removed.
Can it handle very large lists?
Browser memory limits apply, but lists with tens of thousands of short lines typically work fine on modern devices.
Does it modify my original file?
No. You paste text and copy the result — source files on disk are never touched.
Is data uploaded?
No. Deduplication runs entirely in your browser.