Extended ASCII Lookup

Extended ASCII Lookup: Core Features and Principles

When dealing with legacy systems, character encoding conversions, or learning the Extended ASCII character set, quickly locating the encoding value for a special symbol can be a headache. The Extended ASCII Lookup tool is designed specifically to solve this pain point. Simply enter a character or a decimal/hexadecimal value to instantly get the complete EASCII encoding information for that character, including decimal, hexadecimal, octal, binary, HTML entities, and character descriptions, enabling bidirectional lookup.

Why Choose Our Extended ASCII Lookup Tool?

• Supports multi-format encoding output: Displays decimal, hexadecimal, octal, binary, and HTML entities all at once, eliminating the need for manual conversion.
• Smart bidirectional lookup: Look up codes by character or reverse lookup characters by encoding value (decimal or hex). The input direction is automatically recognized.
• Simple and intuitive, no learning required: The interface focuses on a single input field and a clear results panel, making it accessible to both developers and non-technical users with zero learning curve.

How to Use

1. Enter an Extended ASCII character in the input box, such as "©", or directly input a decimal value between 0 and 255 (e.g., 169) or a hexadecimal value (e.g., 0xA9).
2. Click the search button or press Enter. The system will automatically parse the input type and execute the corresponding lookup.
3. The results panel will instantly display the corresponding information: character, decimal, hexadecimal, octal, binary, HTML entity (e.g., ©), Unicode code point, and a brief description (e.g., "Copyright sign"). Example: Input "¥", returns: Character: ¥, Decimal: 165, Hexadecimal: A5, Octal: 245, Binary: 10100101, HTML Entity: ¥, Description: Yen sign.

Frequently Asked Questions (FAQ)

• What is the difference between EASCII and standard ASCII?
  Standard ASCII uses 7 binary bits and can only represent characters in the 0-127 range. EASCII (Extended ASCII) extends this to 8 bits, expanding the code range to 0-255. The 128-255 range is used to represent additional Western European letters, currency symbols, drawing characters, etc., and is part of the ISO 8859-1 (Latin-1) character set.
• Why do some characters show an "Out of EASCII range" error?
  This tool is strictly based on the ISO 8859-1 standard and only supports characters with code points from 0 to 255. If you enter Unicode characters outside this range, such as Chinese characters or emojis, the tool will indicate they are not in the table. You will need to use a more general Unicode lookup tool for those.

Important Notes

The input only accepts a single character or a decimal/hexadecimal value between 0 and 255. Batch queries or pasting multi-character text are not supported. For numeric inputs, write decimal numbers directly (e.g., 233), and prefix hexadecimal numbers with "0x" (e.g., 0xE9). The HTML entities in the search results display both named entities (e.g., é) and numeric entities (e.g., é). For actual use, we recommend using named entities in HTML documents to improve readability. This tool performs all queries locally in your browser and does not upload your input data, ensuring your privacy.

Technical Notes & Best Practices

Although EASCII is gradually being replaced by Unicode in modern systems, it still frequently appears when dealing with legacy communication protocols (like certain serial devices), parsing fixed-width byte streams, and maintaining legacy code. We recommend developers prioritize UTF-8 encoding for new, globalized projects, and only use EASCII lookups for interfaces explicitly restricted to the Latin-1 character set. Common input/output examples: Input "é" → Decimal 233, Hexadecimal 0xE9, HTML Entity é; Input 0x80 → Character is € (Euro sign), Decimal 128; Input 0x90 → Invisible control character "DCS", with the control function noted in the description. If you encounter control characters in the hex 0x80-0x9F range, please note that they may have different rendering behaviors across different operating systems.