How to remove duplicate lines from text online
Keep unique lines without changing their order
Example: remove duplicate lines from a text list
Remove duplicate lines while ignoring letter case
Compare lines after trimming surrounding spaces
Keep the first or last occurrence of each line
Clean keyword lists and names before using them
Remove duplicate lines in your browser without an API request
Features explained
Duplicate line removal
Keeps one occurrence of each comparison key and removes subsequent matching lines.
Case-sensitive comparison
The caseSensitive option defaults to true. Uppercase and lowercase versions can remain separate unless you turn it off.
Ignore surrounding whitespace
The trimBeforeCompare option defaults to false. Enable it to ignore leading and trailing whitespace during comparison without trimming the retained output line.
Choose which occurrence to keep
The keep option supports first and last. The default is first, and the last option retains the final matching occurrence while preserving the retained lines' relative order.
Copy the result
Use Copy to copy the processed text. The interface also has a Copied! label for the copied state.
Download the result
Use Download to save the output. The exact filename, file extension, and download format are not established by the scanned code.
Load an example or clear text
Load Example provides an example input, and Clear is available to clear the current text.
Client-side processing
The scanned implementation processes text in the client-side application, with no fetch or API call found for this tool mode.
What can you use it for?
Remove repeated SEO keywords
Clean a line-by-line keyword list before organizing search terms. Use case-insensitive comparison if uppercase and lowercase spellings should count as the same.
Clean lists of names
Remove repeated names from a copied list while retaining the original sequence of the names that remain.
Prepare URL lists
Remove identical URL lines from a text list. The tool compares whole lines, so differently written URLs aren't guaranteed to be treated as equivalent.
Clean copied spreadsheet data
Paste one record per line to remove repeated complete lines. This is a text-based operation, not a spreadsheet-aware duplicate check.
Keep the latest repeated entry
Choose last when you want to retain the last occurrence of each matching line rather than its first occurrence.
Tool information
| Tool mode | keepUniqueLines |
|---|---|
| Processing | Client-side |
| Input | Plain text, one line per entry |
| Case-sensitive comparison | Enabled by default |
| Trim before comparison | Disabled by default |
| Occurrence to keep | First by default; last is also supported |
| Available actions | Copy, Download, Load Example, Clear |
Benefits
- Remove repeated complete lines without manually scanning a list.
- Keep the relative order of the retained lines.
- Choose whether letter case matters during comparison.
- Choose whether surrounding whitespace matters during comparison.
- Keep either the first or last occurrence of each matching line.
Limitations
- The tool compares complete lines, not individual words or parts of a line.
- With the default settings, uppercase and lowercase text can count as different lines.
- Leading and trailing whitespace matters by default.
- When trimming is enabled, whitespace is ignored for comparison but remains in the retained original line.
- The tool does not alphabetically sort the result.
- The scanned code does not establish a maximum input size, supported download extension, or downloaded filename.
How text processing works
The scanned implementation processes text on the client side, and no fetch or API call was found in the keepUniqueLines processing path. This means the tool's duplicate-removal operation does not show a request to a remote API in the inspected code. It does not establish the behavior of every other part of the website, browser extensions, or network services.
Tips
- Start with the default settings when you want to keep the first occurrence of each exact line.
- Turn off caseSensitive when Apple and apple should count as duplicates.
- Enable trimBeforeCompare when extra spaces at the beginning or end should not create separate comparison keys.
- Choose last when the final occurrence of a duplicate line is the one you want to retain.
- Use Load Example to inspect the tool's behavior before pasting your own list.
Frequently asked questions
How do I remove duplicate lines from text online?
Paste your list into Input Text and use Keep Unique Lines to remove repeated complete lines. The default settings distinguish uppercase from lowercase and treat surrounding spaces as significant. Review Unique Lines to check the result.
Can I keep unique lines without changing their order?
Yes. The tool preserves the relative order of retained lines. It does not alphabetically sort the output, and the default first setting keeps the first matching occurrence in its original position.
How do I remove duplicate lines regardless of case?
Yes. Set caseSensitive to false so uppercase and lowercase differences are ignored during comparison. For example, Apple and apple then match, and the retained line keeps its original spelling.
Can I ignore extra spaces when removing duplicate lines?
Yes. Enable trimBeforeCompare to ignore leading and trailing whitespace during comparison. The tool still returns the original retained line, including its surrounding spaces, rather than automatically trimming the output.
How do I keep the last occurrence of each line?
Choose last in the keep option. The tool scans the lines in reverse and reverses the result afterward, allowing it to retain the last matching occurrence while preserving the relative order of the retained lines.
Can I remove duplicate SEO keywords from a list?
Yes. Put each keyword on its own line and use Keep Unique Lines. Set caseSensitive according to your needs. The tool compares complete lines, so it won't identify a keyword repeated only as part of a longer line.
Can I use Keep Unique Lines without uploading a file?
The scanned tool interface accepts pasted text in Input Text, and its processing code runs on the client side. No fetch or API call was found in the processing path. This does not establish the network behavior of every other website component.
Can I copy or download unique lines?
Yes. The interface includes Copy and Download controls for the result. The scanned code does not establish the download's filename or file extension, so check the browser's download behavior for those details.
Does Keep Unique Lines have a maximum text limit?
The scanned implementation does not specify a maximum input length or line count. That doesn't prove every input size will work equally well in every browser. For very large lists, test your text and review the output.
Does the tool sort lines alphabetically after removing duplicates?
No. It preserves the relative order of the lines it keeps. With keep set to first, the first occurrence remains; with keep set to last, the last occurrence is retained without alphabetically sorting the result.