Unicode Encode/Decode

Convert text to various Unicode formats or restore Unicode to text.

Unicode Encoding
Convert text to Unicode escape sequences
Length: 0 charactersCode Point: 0Size: 0 bytes

What is Unicode?

Unicode is a universal character encoding standard that assigns a unique code point to every character. It allows computers to consistently represent and manipulate text in most of the world's writing systems.

Unicode supports over 140,000 characters covering 150 modern and historic scripts, as well as symbols, emoji, and other notations. Unicode escape sequences are ways to represent these characters in programming languages and data formats.

Common Uses of Unicode Encoding/Decoding

  • Internationalization (i18n): Ensuring software can work with text in any language.
  • Data Processing: Handling text data with special characters in various programming environments.
  • Security: Encoding special characters to prevent injection attacks or to safely store text in databases.
  • Debugging: Identifying invisible or confusing characters in text data.

How Unicode Works

Unicode assigns each character a unique code point, which is a numerical value. These code points are typically written in hexadecimal format, prefixed with 'U+', such as U+0041 for the letter 'A'.

Unicode Encoding Forms:

UTF-8: Variable-length encoding (1-4 bytes per character). Efficient for ASCII text, as ASCII characters use just 1 byte.

UTF-16: Uses 2 or 4 bytes per character. Common in many programming environments (JavaScript, Java, .NET).

UTF-32: Fixed 4 bytes per character. Simpler to process but uses more storage.

Decoding Process:

When decoding, the software reads the encoded bytes and maps them back to the corresponding Unicode code points, then displays the appropriate characters.

Unicode Escape Sequence Formats

Different programming languages use different formats for Unicode escape sequences:

JavaScript: \u0041 for BMP characters, \u{1F600} for others

Python: \u0041 for BMP, \U0001F600 for others

C#: \u0041 for BMP, surrogate pairs for others

Unicode Example Analysis

Let's examine how different characters are represented in Unicode:

Character Examples:

H = U+0048
i = U+0069

Unicode Code Point:

U+0048 U+0069

UTF-8 Representation (bytes):

48 69

UTF-16 Representation (bytes):

00 48 00 69

Unicode escape sequence:

\u0048\u0069

Common Mistakes with Unicode

  • Encoding Form Confusion: Mixing up UTF-8, UTF-16, and UTF-32 or not specifying the encoding form explicitly.
  • Byte Order Mark (BOM) Issues: Not handling the BOM correctly when processing Unicode text files.
  • String Length Miscalculation: Assuming one character equals one code unit or one byte.
  • Normalization Problems: Not normalizing Unicode text can lead to comparison issues (e.g., é can be represented in multiple ways).
  • Surrogate Pair Handling: Incorrectly splitting surrogate pairs in UTF-16 encoded text.