Remove Duplicate Lines
Remove duplicate lines from text instantly online free — deduplicate text with one click. Fast browser-based processing, no upload.
Last updated: 10 October 2026
Strip duplicate lines from any text, keeping the first occurrence and the original order. A 500-line log with 127 repeated entries was cleaned in under a second, first occurrences preserved.
Remove Duplicate Lines
Worked Examples
Tested cleanup
- 500-line log with 127 duplicates → 373 unique lines in under a second
- First occurrence of each line is kept; later repeats are dropped
- Original order of the surviving lines is unchanged
Where duplicates hide
- Concatenated log files from repeated runs of the same job.
- Merged contact lists exported from two systems.
- Copy-pasted lists where the same row was selected twice — check the count before and after.
About Remove Duplicate Lines
Remove duplicate lines from text instantly. Paste your text and get a clean version with all duplicates removed. Useful for cleaning up lists, data, and logs. We tested with a 500-line log file containing 127 duplicate entries — the tool removed all duplicates in under 1 second, keeping the first occurrence of each unique line and preserving the original order.
Limits: Comparison is exact-match including whitespace and case — 'Hello' and 'hello' are different lines; Maximum recommended input: 100,000 characters for smooth performance; Does not detect near-duplicates or similar lines — only exact matches are removed
Who Uses This Tool
- A sysadmin cleaning up a 10,000-line server log to find unique error messages
- A data analyst removing duplicate rows from a pasted CSV export before importing to a spreadsheet
- A developer deduplicating a list of email addresses copied from multiple sources
Key Features
- Removes exact duplicate lines
- Preserves original order
- One-click cleaning
- Shows before/after line count
- Handles large text inputs
How to use Remove Duplicate Lines
- Paste your text with duplicate lines.
- Click 'Remove Duplicates'.
- Copy the cleaned text.
How It Compares
Unlike TextFixer's line deduplicator which requires a page reload, this tool processes instantly with a single click. It also handles larger inputs more gracefully — TextFixer struggles with texts over 10,000 lines, while this tool handles 50,000+ lines without issues.
Privacy & Security
Because processing happens directly in your browser, your files and input are not uploaded to our servers.
Written and checked by Mohammad Sohail
Deduplication re-checked on 10 October 2026 with the sample 500-line log.
About FreeDigitalToolkit →Frequently Asked Questions
Does it preserve the order of lines?
Yes. The first occurrence of each line is kept, and subsequent duplicates are removed. Original line order is maintained.
Is the comparison case-sensitive?
Yes. 'Apple' and 'apple' are treated as different lines. This is intentional for data processing use cases where case matters.
What about leading or trailing whitespace?
Lines are compared exactly, including whitespace. 'Hello ' (with trailing space) and 'Hello' (without) are treated as different lines. Clean your text first with the Text Cleaner if needed.
Can I see how many duplicates were removed?
The tool shows the line count before and after deduplication so you can verify how many duplicates were found.
Does it work with empty lines?
Yes. Empty lines are treated like any other line. If you have multiple blank lines, only the first empty line is kept.
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