Best Free Online Developer Tools to Use in 2026
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
Duplicate Line Remover
Remove duplicate lines from text with case-sensitive, preserve order, trim whitespace, and show count options.
Duplicate Line Remover
Enter text to remove duplicate lines
- Paste your text — Enter or paste any text with duplicate lines in the input area.
- Configure options — Toggle case sensitivity, preserve order, trim whitespace, or show duplicate counts.
- Click "Remove Duplicates" — The tool processes your text and shows the deduplicated result.
- Copy the result — Use the Copy button to copy the cleaned text to your clipboard.
Options Explained
Case Sensitive
When enabled, "Hello" and "hello" are treated as different lines. When disabled, they are considered duplicates regardless of case.
Preserve Order
Keep the original order of lines based on their first occurrence. When disabled, duplicates are still removed but based on first occurrence order.
Trim Whitespace
Remove leading and trailing whitespace from each line before comparing. Useful when lines have inconsistent spacing or indentation.
Show Count
Append the occurrence count to duplicate lines (e.g., "hello (3x)"). Non-duplicate lines are shown without a count.
What counts as a duplicate line?
A duplicate line is any line that is identical to a previous line in the text. When "Case Sensitive" is off, "Line" and "line" are treated as the same.
How are blank lines handled?
Blank lines are treated as regular lines. If there are multiple blank lines, only the first one is kept (when "Trim Whitespace" is off). Enable "Trim Whitespace" to treat all blank lines as identical.
Is my data sent to a server?
No. All processing happens entirely in your browser. Your text never leaves your device.
What is the maximum text size?
There is no hard limit, but very large texts (100,000+ lines) may cause slower performance in the browser. The tool handles most practical use cases efficiently.
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