Text Tool
AI Text Cleaner | Keep Formatting, Strip Hidden Junk
Removes non-breaking spaces, curly quotes, and invisible characters from Claude and ChatGPT pastes while keeping bold, links, and headings intact.
Remove Duplicate Lines
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Output
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Input Lines
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Unique Lines
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Duplicates Removed
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Reduction
Removing duplicate lines from a list is one of the most common data-cleaning tasks when working with CSV exports, keyword lists, email addresses, log files, or any text data that may contain repeated entries. This tool processes the input in your browser and outputs only unique lines, with no data sent to any server.
When to Use This Tool
Marketing and SEO professionals use it to deduplicate keyword lists before uploading to campaigns or analysis tools. Developers use it to clean log output or deduplicate import files before database operations. Data analysts use it as a first step in list normalisation before applying further transformations. The case-sensitive option matters here: “Apple” and “apple” are treated as distinct entries by default but can be collapsed with case-insensitive mode.
How the Deduplication Works
The tool splits the input on newline characters. Each line is optionally trimmed of leading and trailing whitespace before comparison. A hash set tracks which values have been seen. The first occurrence of each unique line is kept. All subsequent occurrences are discarded. The output preserves the original order of first appearances unless the sort option is enabled, which then arranges the unique results alphabetically.
Frequently Asked Questions
It removes all duplicates throughout the entire input, not just consecutive ones. The tool tracks every line it has already seen using a lookup object. When a line appears again at any position in the input, it is removed. The first occurrence is kept in its original position unless the sort option is enabled.
In case-sensitive mode (the default), 'Apple' and 'apple' are treated as two distinct lines and both are kept. In case-insensitive mode, they are treated as the same and only the first occurrence is kept. Case-insensitive mode is useful for email address lists, keyword lists, and domain lists where capitalisation varies but the underlying value is the same.
Yes. The tool works on any text where each unique idea, item, or value occupies its own line. This includes CSV files where each row is a separate line, log files where each event is a line, keyword lists, email lists, URL lists, and any structured data where line breaks serve as delimiters between distinct records.