Left Parenthesis (

The Left Parenthesis character (() is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference (, the decimal numeric character reference (, or the hexadecimal numeric reference (. The character is assigned Unicode code point U+0028 in the Universal Character Set.

The left parenthesis is one of the most fundamental grouping characters in mathematics, programming, and written language. It denotes function calls, expression grouping, and parenthetical remarks. While it never needs escaping in standard HTML, the entity exists for completeness and edge-case encoding needs.

Technical character entities represent brackets, delimiters, and punctuation marks that frequently require escaping in HTML source code and programming contexts. Characters like curly braces, square brackets, pipes, and backslashes often carry special meaning in templating engines, regular expressions, or markup parsers, making their explicit HTML entity encoding important for preventing unintended interpretation by the browser or build tools.

When deciding how to encode the Left Parenthesis character in your HTML documents, the named entity ( is generally the most readable choice for developers reviewing or maintaining source code. The decimal form ( and hexadecimal form ( are equally valid alternatives that work in contexts where named entities may not be supported, or when generating HTML output programmatically from server-side code. All three representations produce identical visual output in every modern web browser.

Use the left parenthesis entity in rare cases where the literal ( character might be misinterpreted, such as in URL generation or template engine contexts. In standard HTML text content, parentheses can be typed directly without issues.