🔤 Remove Duplicate Characters

📝 Input Text

Duplicate characters will be removed according to your settings

⚙️ Processing Options

Case sensitive (treat'A' and'a' as different) Preserve whitespace (keep all spaces, tabs, newlines) Keep first occurrence (uncheck to keep last)

Configure how duplicate characters are processed

⚡ Quick Actions

🏷️ Current Settings

Case Sensitivity: {{ caseSensitive ?'Enabled' :'Disabled' }}

Preserve Whitespace: {{ preserveWhitespace ?'Yes' :'No' }}

Keep: {{ firstOccurrence ?'First occurrence' :'Last occurrence' }}

📤 Processed Text

{{ result }}

📊 Processing Statistics

Original:

Length: {{ stats.original.length }}

Unique Chars: {{ stats.original.uniqueChars }}

Result:

Length: {{ stats.result.length }}

Unique Chars: {{ stats.result.uniqueChars }}

Reduction:

Duplicates Removed: {{ stats.duplicatesRemoved }}

Percentage: {{ stats.percentageReduction }}%

Duplicates:

Total Found: {{ stats.totalDuplicates }}

🔍 Duplicate Characters Found

{{ dup.char ==='' ?'(space)' : dup.char ==='\t' ?'(tab)' : dup.char ==='\n' ?'(newline)' : dup.char }} at position {{ dup.position }} (first at {{ dup.firstPosition }})

Showing first 20 of {{ stats.totalDuplicates }} duplicates

💡 Examples

Basic deduplication:

Input:"Hello World"

Output:"Helo Wrd" (removes duplicate'l' and'o')

Case insensitive:

Input:"Programming"

Output:"progamin" (removes duplicate letters)

Keep last occurrence:

Input:"abcabc"

Output:"abc" (keeps the last'a','b','c')

⚠️ {{ error }}

🔄 Processing text...

ℹ️ About Remove Duplicate Characters

Remove Duplicate Characters Tool deduplicates characters in text while keeping the order predictable. Use it as a unique character extractor, repeated-letter remover, or text cleanup helper when you need one copy of each character instead of a full word or line deduplication pass.

The tool can keep either the first occurrence or the last occurrence of each repeated character. For example, banana becomes ban when first occurrences are kept, while abcabc still returns abc when the later a, b, and c replace their earlier positions. Turn off whitespace preservation when spaces, tabs, and line breaks should be deduplicated too.

Common uses:

Build a unique character set from sample text, identifiers, or training data.
Remove accidental repeated keystrokes such as heellooo!!!.
Compare character coverage before creating regex character classes, fonts, or test fixtures.
Clean OCR or scraped text where duplicate glyphs were introduced during extraction.
Inspect how much repeated punctuation, spacing, or casing contributes to noisy text.

Processing options:

Case sensitive: Treat A and a as different characters, or merge them using case-insensitive comparison.
Preserve whitespace: Leave every space, tab, and newline in place, or include whitespace in the duplicate check.
Keep first/last: Choose whether the earliest or latest copy of a repeated character survives.

The implementation works on JavaScript string iteration, which follows Unicode code points rather than raw UTF-16 code units. That is safer for emoji and many non-BMP characters, but it is not full grapheme-cluster segmentation: a flag emoji, skin-tone sequence, or letter plus combining mark may contain multiple code points. See the ECMAScript string iterator, Unicode Text Segmentation (UAX #29), and Unicode Normalization Forms (UAX #15) for the underlying text model.

Limitations: Canonically equivalent text is not normalized before comparison, so é and é can be treated differently unless you normalize the input first. Case-insensitive mode uses locale-aware lowercasing, not full linguistic collation, and this tool is not a password-strength or data-loss prevention control. Review the output before replacing original data.

API Usage Example:

POST /api/tools/text/remove-duplicate-characters
Content-Type: application/json

{
    "text": "Hello World!!!",
    "caseSensitive": true,
    "preserveWhitespace": true,
    "firstOccurrence": true
}