Greek Capital Letter Eta Η

The Greek Capital Letter Eta character (Η) is a standard HTML entity defined in the HTML specification. In HTML source code, it can be written using the named entity reference Η, the decimal numeric character reference Η, or the hexadecimal numeric reference Η. The character is assigned Unicode code point U+0397 in the Universal Character Set.

Greek capital eta is visually identical to the Latin capital letter H. It appears in Greek-language text and is the origin of the Latin H. In scientific contexts, the lowercase η (efficiency, viscosity) is far more commonly encountered.

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 Capital Letter Eta character in your HTML documents, the named entity Η is generally the most readable choice for developers reviewing or maintaining source code. The decimal form Η and hexadecimal form Η 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 capital eta entity in Greek-language text and linguistic discussions about the evolution from Greek eta to Latin H. In scientific notation, the lowercase η is standard for representing efficiency and viscosity.