Quickly strip repeated lines of text while preserving order. Case-insensitive or exact match, sorting and more — all in your browser.
🆓 Free to Use⚡ Instant Processing🔒 100% Private🚫 No Registration
Remove Duplicate Lines Tool
🔒 Your text is processed entirely in your browser. Nothing is uploaded to our servers.
Input
Lines: 0 · Chars: 0 · Words: 0
Output
Lines: 0 · Chars: 0 · Words: 0
Advanced Options
Duplicate Analysis
Duplicates Removed
0
Unique Remaining
0
Blank Lines Detected
0
Duplicate %
0%
Duplicate Line Preview
How to Remove Duplicate Lines in 3 Steps
1
Paste Your Text
Type, paste, or load a text file into the Input panel — one item per line works best.
2
Choose Matching
Pick Exact, Case-Insensitive, Trim, or Combined. Open Advanced Options for sorting or empty-line rules.
3
Remove & Copy
Click "Remove Duplicate Lines". Copy or download the cleaned output — your data never leaves the browser.
Remove Duplicate Lines from Text Online
Whether you're cleaning a list of email addresses, names, tags, URLs or log lines, repeating entries clutter your work and waste space. Sigify's Remove Duplicate Lines tool lets you dedupe any text instantly in your browser — no signup, no upload, no tracking.
How does Remove Duplicate Lines work?
The tool splits your input by line breaks, then walks each line in original order and keeps only the first occurrence of each unique line based on your chosen match mode. The remaining lines preserve the original order (unless you opt in to sorting).
🎯
Exact Match
Removes lines that are byte-for-byte identical.
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Case-Insensitive
Treats "Apple" and "apple" as duplicates.
✂️
Trim Whitespace
Ignores leading and trailing spaces when comparing.
📁
Open .txt Files
Load any plain text file from your device for cleanup.
📊
Duplicate Stats
See how many duplicates were removed and the duplicate percentage.
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100% Private
Processing happens in your browser. Nothing is uploaded.
Common Use Cases
This tool is perfect for cleaning email lists, removing duplicate CSV rows (column-by-column), deduplicating tags, sanitising log files, merging two name lists while keeping uniques, or just organising copy-pasted notes.
Privacy First
Sigify doesn't run any backend for this tool. Open the page, paste your text and the JavaScript does the rest. Close the tab and your data vanishes. We literally cannot see your text.
Everything you need to know about deduping text online.
It reads your text line by line and keeps only the first occurrence of each unique line. The output preserves the original order unless you turn on sorting.
By default we use Case-Insensitive + Trim matching — "Apple ", "apple" and " APPLE" collapse to one line. You can switch to Exact Match to keep case-sensitive differences.
No. All processing happens locally in your browser via JavaScript. Nothing is uploaded or stored.
Yes. Open Advanced Options and choose A→Z, Z→A, Numeric Ascending/Descending, or Natural Sort (which mixes digits and letters naturally: File 2 before File 10).
Yes — the algorithm uses Set/Map lookups so it handles tens of thousands of lines without freezing the page.
Yes. Click "Open file" in the Input panel to load any plain text file from your device.
Yes — completely free, no signup and no limits.
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