🧹 Duplicate Line Remover

📝 Text Input

Duplicates will be detected and removed automatically

⚙️ Processing Options

⚡ Quick Actions

📊 Processing Statistics

Original Lines
{{ stats.originalLines }}
Unique Lines
{{ stats.uniqueLines }}
Duplicates Removed
{{ stats.duplicatesRemoved }}
Reduction
{{ stats.reductionPercentage }}%

✨ Cleaned Text (No Duplicates)

{{ outputText }}
{{ stats.uniqueLines }} unique lines ({{ stats.duplicatesRemoved }} duplicates removed)

🔍 Duplicate Analysis

{{ duplicate.line }}
Found {{ duplicate.count }} times

✨ Cleaned Text

Enter text above to remove duplicate lines...

⚠️ {{ error }}

ℹ️ About Duplicate Line Remover

Duplicate Line Remover deduplicates plain-text lists one line at a time. It keeps the first matching line by default, so non-adjacent repeats such as names, IDs, URLs, hostnames, log messages, CSV rows, or inventory values can be collapsed without manually sorting the input first.

This is similar to the Unix uniq family of text filters, but with browser-friendly options for case-insensitive comparison, trimming leading and trailing whitespace, keeping or dropping blank lines, and sorting the final unique list. For command-line behavior, see the POSIX uniq utility and GNU Coreutils uniq documentation.

Common uses:

  • Clean repeated entries from pasted spreadsheets, CSV exports, allowlists, blocklists, and email lists.
  • Reduce repeated log lines, error messages, usernames, domains, IP addresses, or URL lists before analysis.
  • Prepare unique values for scripts, configuration files, access-control rules, reports, or database imports.
  • Compare how many rows were removed with the built-in original, unique, duplicate, and reduction statistics.

How matching works:

  • Preserve order: keep the first occurrence of each unique comparison key.
  • Case sensitivity: choose whether Line, line, and LINE are treated as the same value.
  • Whitespace trimming: optionally compare and output trimmed lines, so apple and apple can match.
  • Blank lines: drop empty lines by default, or keep one blank line as a deduplicated value.
  • Sorting: optionally alphabetize the unique output after duplicates are removed.

Example: with the default case-insensitive, trim-whitespace settings, input apple, banana, Apple , banana returns apple, banana. Turn on case-sensitive comparison when capitalization is meaningful, such as product codes, identifiers, or source data where ID and id must remain separate.

Limitations: this is a line-based text cleaner, not a semantic CSV parser or database merge tool. It compares whole lines after the selected normalization rules, so it will not detect duplicates based on a single CSV column, fuzzy spelling, reordered fields, Unicode normalization differences, or locale-specific collation rules. Very large pasted files may also be limited by browser memory and textarea performance.

Privacy: routine line cleanup runs in your browser as you type. The API example below is available for automated workflows when you intentionally want server-side processing.

API Usage Example:

POST /api/tools/text/duplicate-line-remover
Content-Type: application/json

{
    "text": "apple\nbanana\napple",
    "caseSensitive": false,
    "trimWhitespace": true,
    "keepEmptyLines": false,
    "sortResults": false
}
Ready