GPT CLEAN UP

GPT CLEAN UP

Free online text processing tools

ChatGPT Unicode Normalizer

Normalize Unicode text to NFC, NFD, NFKC, or NFKD form to eliminate hidden code-point variants.

What Is Unicode Normalization?

Unicode normalization is a process that transforms text into a standardized, canonical form to ensure consistent representation across systems and applications. This is important because Unicode often provides multiple ways to represent what appears to be the same character or symbol, leading to potential inconsistencies in text processing, comparison, and storage.

For example, the character "é" (e-acute) can be represented in Unicode as either:

  • A single code point: U+00E9 (é) - precomposed form
  • Two code points: U+0065 (e) + U+0301 (´) - decomposed form

To human eyes, these representations look identical, but to computers, they're entirely different character sequences, leading to confusion in text processing, search operations, and data handling.

Why Normalize ChatGPT Output?

ChatGPT and other AI text generators often produce content with inconsistent Unicode representations. This happens because:

  • AI models are trained on diverse datasets with varying Unicode representations
  • The model may generate text using different normalization forms in the same output
  • Special characters, particularly in non-English text, may use inconsistent code point sequences
  • Copy-paste operations from various sources into prompts can introduce mixed normalizations

These inconsistencies can cause various problems:

  • String comparison failures (e.g., "café" ≠ "café" when normalized differently)
  • Search and replace operations that miss matches
  • Incorrect sorting and indexing in databases
  • Hashing discrepancies in security applications
  • Storage inefficiencies due to unnecessary code points
  • Encoding issues when transferred between systems

Normalization Forms Explained

FormFull NameDescriptionBest For
NFCNormalization Form C
(Canonical Composition)
First decomposes characters, then recomposes them by canonical equivalence. Results in composed characters where possible.
  • Web applications
  • Most modern systems
  • Databases
  • General text processing
NFDNormalization Form D
(Canonical Decomposition)
Decomposes characters by canonical equivalence, separating base characters from combining marks.
  • macOS filesystems
  • Linguistic analysis
  • Character-by-character processing
NFKCNormalization Form KC
(Compatibility Composition)
Performs compatibility decomposition, then canonical composition. Replaces compatibility characters with their equivalents.
  • Search engines
  • Indexing
  • Content comparison
  • Security applications
NFKDNormalization Form KD
(Compatibility Decomposition)
Performs compatibility decomposition, which replaces characters with their compatibility equivalents and separates them.
  • Text transformation
  • Most aggressive normalization
  • Converting styled text to plain

Note: Compatibility forms (NFKC/NFKD) are more aggressive and may change the appearance of text, while canonical forms (NFC/NFD) preserve visual appearance. For general text processing, NFC is the most commonly recommended form.

Examples of Normalization Changes

Canonical Forms (NFC/NFD)

  • é (U+00E9) ↔ e+´ (U+0065+U+0301)
  • ñ (U+00F1) ↔ n+˜ (U+006E+U+0303)
  • ç (U+00E7) ↔ c+¸ (U+0063+U+0327)
  • (U+D55C) ↔ ++ (U+1112+U+1161+U+11AB)

Compatibility Forms (NFKC/NFKD)

  • (U+2460) → 1 (U+0031)
  • ½ (U+00BD) → 1/2 (U+0031+U+002F+U+0032)
  • (U+FB01) → fi (U+0066+U+0069)
  • (U+2115) → N (U+004E)
  • (U+3392) → km² (U+006B+U+006D+U+00B2)

Common Use Cases

  • Text Processing and Comparison: Ensure consistent string comparison regardless of how characters were originally encoded
  • Database Operations: Normalize strings before storing in databases to ensure consistent searching, sorting, and indexing
  • Security Applications: Prevent "canonical equivalence" attacks where different-looking but similar strings bypass security measures
  • Natural Language Processing: Create consistent input for NLP algorithms and language analysis
  • Search Engine Optimization: Ensure URLs and content are consistently normalized for better indexing
  • File and Resource Names: Prevent duplicate files with visually identical but technically different names
  • Internationalization: Properly handle text in multiple languages with different character representations

How to Use the Unicode Normalizer

  1. Choose a Normalization Form:
    • NFC: For general use and web applications (most common)
    • NFD: For macOS compatibility or when you need decomposed characters
    • NFKC: When you need semantic equivalence for search or comparison
    • NFKD: For the most aggressive normalization
  2. Input Your Text: Either paste text directly or upload a file containing Unicode text
  3. Process the Text: Click "Normalize Unicode" to apply the selected normalization form
  4. Review the Results: Check the normalization statistics to see what changes were made
  5. Use the Normalized Text: Copy the normalized output for your application

Privacy and Security

Our Unicode Normalizer tool processes all text and files entirely in your browser. Your data never leaves your device, and no information is sent to our servers. This ensures complete privacy and security, making it safe for processing sensitive or confidential information.