Unicode to HTML/CSS Entity Converter

Systems that cannot handle UTF-8 will silently corrupt your content. An unescaped © in an email template or a → in legacy CMS output can render as garbage bytes, breaking layouts and losing meaning. This tool converts every non-ASCII Unicode code point to its correct HTML named entity (e.g., ©), numeric HTML entity (e.g., ©), or CSS escape sequence (e.g., \00A9). ASCII characters in the printable range 0x20 - 0x7E pass through untouched. The converter references a dictionary of over 250 named HTML entities defined in the HTML5 specification. Characters without a named entity receive a hexadecimal numeric entity. This tool approximates a build-step encoder; it does not validate whether your target system supports HTML5 named entities versus the older HTML4 subset.

The converter iterates each character in the input string. For each character, it extracts the Unicode code point using codePointAt. The decision logic follows:

Where cp is the Unicode code point of the character, HEX is the uppercase hexadecimal representation of cp zero-padded to at least 4 digits, and name is the HTML5 named entity key (without the ampersand and semicolon). The five HTML-significant ASCII characters (&, <, >, ", ") are always converted even though they fall in the ASCII printable range, because they have syntactic meaning in HTML/CSS contexts.