Greek Small Letter Xi ξ

The Greek Small Letter Xi character (ξ) is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference ξ, the decimal numeric character reference ξ, or the hexadecimal numeric reference ξ. The character is assigned Unicode code point U+03BE in the Universal Character Set.

Xi is the fourteenth letter of the Greek alphabet, featuring a distinctive zigzag form. In mathematics, it often serves as a dummy variable or represents specific functions. In physics, it appears in various specialized contexts. The letter's complex shape makes it one of the more challenging Greek letters to handwrite.

Greek letter entities are indispensable for scientific papers, engineering documentation, statistical analyses, and mathematical content published on the web. From physics equations using alpha and omega to statistical formulas featuring sigma and mu, these entities allow content authors to include Greek characters reliably without requiring specialized fonts or complex Unicode input methods on the keyboard.

When deciding how to encode the Greek Small Letter Xi character in your HTML documents, the named entity ξ is generally the most readable choice for developers reviewing or maintaining source code. The decimal form ξ and hexadecimal form ξ 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 xi entity in mathematical expressions where a specialized variable name is needed, in physics equations, and in discussions of the Greek alphabet. The HTML entity avoids the difficulty of typing this character, which is not available on standard keyboards.