Greek Capital Letter Xi

Greek Capital Letter Xi is a Greek-alphabet character used both for writing the modern Greek language and, more commonly online, as mathematical or scientific notation — for constants, variables, angles, and units across physics, engineering, and statistics.

Unicode block: Greek and Coptic (U+0370–U+03FF). This block encodes the modern Greek alphabet alongside Coptic letters. Greek letters have been borrowed into mathematics, physics, and engineering notation for centuries, which is why you'll see them constantly outside actual Greek-language text.

At Unicode code point U+039E (decimal 926), Greek Capital Letter Xi is the 39th of 135 characters cataloged in this category on How To Type Any Symbol. In terms of typing methods, like most characters outside the 0–255 legacy codepage range, it has no dedicated Alt-code or single-key shortcut on Windows or Mac, so copy-paste is the standard, universal method for typing it. Regardless of platform, clicking the copy button above places the exact character on your clipboard, ready to paste into any application that accepts Unicode text.

💡 Good to know: LaTeX and most math-typesetting tools have a dedicated command for every Greek letter (e.g. \alpha, \beta), which is usually faster than copy-pasting for technical documents.