Highlight Duplicate Lines

Paste text to highlight duplicate lines with count, detect repeated entries, and analyze frequency instantly. You can ignore case, trim spaces, skip empty lines, show only duplicates, and sort by occurrence count. All processing runs locally in your browser.

Paste your text below to detect and highlight duplicate lines. This tool identifies repeated lines, highlights them, and shows how many times each duplicate occurs.

⚙ Options

No input yet.

⭐ About Highlight Duplicate Lines with Count

The Highlight Duplicate Lines with Count tool helps you detect repeated lines in multiline text. It highlights duplicate lines and shows the total number of occurrences next to each duplicate while keeping your original text order unless you choose sorting.

⚙️ How duplicate line detection works

  • Each line is compared exactly as written by default.
  • Every repeated line is highlighted in the output preview.
  • A duplicate count like (3x) is shown next to each duplicate line.
  • Original order is preserved unless you enable sort by occurrence count.

⚙️ Available options

  • Ignore case to treat Apple and apple as the same line.
  • Ignore leading/trailing spaces for cleaner comparisons.
  • Ignore empty lines so blank lines are excluded from analysis.
  • Show only duplicate lines to hide all unique lines.
  • Sort by occurrence count with None, High - Low, or Low - High.

🔎 Example

Input:

apple
banana
apple
orange
banana
banana

Output (None):

apple (2x)
banana (3x)
apple (2x)
orange
banana (3x)
banana (3x)

Output (High - Low):

banana (3x)
banana (3x)
banana (3x)
apple (2x)
apple (2x)
orange

Output (Low - High):

apple (2x)
apple (2x)
banana (3x)
banana (3x)
banana (3x)
orange

🔎 Common use cases

  • Dataset cleaning and duplicate entry analysis.
  • Keyword and phrase frequency inspection in text lists.
  • Log file debugging to find repeated events quickly.
  • Validating repeated records before CSV or database import.

⚠️ Notes

  • All processing happens in your browser for privacy.
  • Sorting changes display order only and does not modify line content.
  • Copy and download include the visible output including duplicate counts.

Frequently Asked Questions

It finds repeated lines in your text, highlights duplicate lines in the preview, and shows how many times each duplicate occurs.

By default, lines are compared exactly as written, so case, spaces, and empty lines are treated as part of the line.

Yes. Enable Ignore case to treat lines like Apple and apple as duplicates.

Yes. Enable Ignore leading/trailing spaces to compare trimmed values while preserving original line content in the output.

Yes. Enable Ignore empty lines to skip blank lines during analysis and output generation.

It hides unique lines and displays only lines that appear more than once, each with its occurrence count.

You can keep the original order, sort from highest frequency to lowest, or from lowest to highest. Lines with equal counts keep their original relative order.

No. Sorting only changes how lines are displayed in the output. It does not edit your original input text.

Yes. You can upload a TXT file and process it directly in the browser.

Yes. Use Copy to copy the output and Download .txt to save it as a text file.

No. All duplicate line detection runs locally in your browser and your text is not uploaded.