German ALT Codes

What the umlaut actually does. Despite looking similar to a diaeresis (¨), the umlaut isn't a diacritic — it's a historical shorthand. It originally represented a small e written above the vowel to indicate a sound shift. The sound moves toward the front of the mouth: a (ah) → ä (eh), o (oh) → ö (rounded "uh"), u (oo) → ü (rounded "ee"). This is why if you can't type umlauts, the standard substitution is ae, oe, ue — that's the original pre-umlaut spelling.

The eszett (ß) is not a beta. It looks like a Greek β but it's actually a ligature of two letters: long s (ſ) + z. In modern usage it represents a sharp ss sound. Rules for when to use ß versus ss changed in the 1996 spelling reform: ß after long vowels and diphthongs (Straße, heißen), ss after short vowels (Fluss, müssen). Switzerland abandoned ß entirely — Swiss German always writes ss.

The capital ẞ exists but is rarely used. In 2017 the Council for German Orthography officially added a capital-case ß (ẞ, Unicode U+1E9E). Before this, words containing ß were written with SS when capitalized: Straße → STRASSE. Most German text, signage, and documents still follow the SS convention. The capital ẞ has no classic ALT code — use Unicode input.

Names with umlauts can be transliterated. In contexts where umlauts aren't available (email addresses, passport MRZ lines, older software), Müller becomes Mueller, Gött­ingen becomes Goettingen. This is officially sanctioned, but in a word processor or browser, proper umlauts are always preferred.