Remove Duplicate Lines
Remove duplicate lines from pasted text while keeping the first or last occurrence in order. Your text is processed locally in your browser.
Working · Browser-onlyRemove Duplicate Lines Online
Remove Duplicate Lines online with clear matching, cleanup, and retention controls. The approved processor is designed to run locally in the browser; all other processors remain disabled until separately validated.
Primary toolProcessed locally in your browser
Featured Tools
Browse All ToolsOne clean workspace for everyday text
Case Converter
Change text to upper, lower, title, sentence, or toggle case.
Planned · Processor disabledWhitespace Remover
Clean extra spaces, tabs, and blank lines without merging words.
Planned · Processor disabledSort Lines
Arrange lines alphabetically, numerically, or in natural order.
Planned · Processor disabledReverse Text
Reverse characters, words, or lines with Unicode-aware controls.
Planned · Processor disabledFind and Replace
Find exact text or patterns and replace selected matches.
Planned · Processor disabledWord Counter
Count words and estimate reading time with clear token rules.
Planned · Processor disabledCharacter Counter
Measure characters, spaces, code points, and bytes.
Planned · Processor disabledCase-Insensitive Dedupe
Remove matching lines even when letter case differs.
Planned · Processor disabledText Diff Checker
Compare two texts and reveal line, word, or character changes.
Planned · Processor disabledRemove Empty Lines
Delete blank lines or collapse repeated gaps into one.
Planned · Processor disabledAdd or Remove Line Numbers
Add structured line numbers or remove existing numbering.
Planned · Processor disabledPrefix or Suffix Lines
Add consistent text before or after selected lines.
Planned · Processor disabledCSV Column Extractor
Extract one CSV column while respecting headers and quotes.
Planned · Processor disabledSlug Generator
Turn titles into clean, reusable URL slugs.
Planned · Processor disabledUnicode Normalizer
Normalize Unicode forms and identify invisible characters.
Planned · Processor disabledDesigned for confidence
Clear choices. Checkable results. Honest limits.
Only the approved Remove Duplicate Lines processor is eligible for activation. Planned processors stay disabled until separately validated.
Private where verified
Tool text stays in the browser processing path.
Options with purpose
Every control has a documented effect.
Results you can check
Separate counts support verification.
Frequently asked questions
Clear answers before you clean a list
How do I remove duplicate lines from text?
Paste one item per line, choose the matching options, run the tool, and verify the counts before copying.
Can I remove duplicate lines without changing their order?
Yes. The retained lines remain in their original relative order.
Can duplicate matching ignore uppercase and lowercase?
Yes. Turn off case-sensitive matching when capitalization should not distinguish lines.
Can I keep the last occurrence?
Yes. Choose Last occurrence before running the tool.
How are blank lines handled?
Preserve every blank line, keep one repeated blank, or remove all blank lines.
Why do visually identical lines sometimes remain?
Hidden spaces, letter case, Unicode composition, and line endings can make lines technically different.
Is tool text uploaded?
The processor is designed to operate in the browser without sending tool text to WordPress.
Can I process CSV rows?
Use a structure-aware CSV workflow; newline-based cleanup is not a CSV parser.
How can I verify a result?
Compare input, duplicate, blank-line, and output counts, then spot-check retained values.
Does it work on mobile?
The workspace is responsive, although large lists are usually easier to review on a desktop.