German ß Eszett: When to Write ß and When to Write ss
The German ß Eszett (also called scharfes S, “sharp s”) is a letter for a voiceless “s” sound, and Germans and Austrians still use it every day. The rule since the spelling reform: write ß after a long vowel or a diphthong (Straße, groß, heißen) and ss after a short vowel (Fluss, muss, dass). Switzerland writes ss everywhere.
What is ß?
ß is one letter, not two. Its name Eszett (“s-z”) comes from its history: it developed from a ligature of the old long s (ſ) with a z or an s. Three facts to know:
- Sound: always a voiceless [s], as in English “bus”.
- Position: it never starts a word. You find it inside or at the end: Straße, Fuß.
- Case: the lowercase ß is everywhere; a capital ẞ also exists (more below).
ß is not one of the 26 letters of the basic alphabet. German teachers usually present it together with ä, ö and ü as the extra letters.
Do Germans still use ß?
Yes. In Germany and Austria, ß is part of standard spelling in schools, newspapers, official documents and job applications. The spelling reform (agreed in 1996, revised in 2006) reduced the number of words with ß but did not abolish it. What changed is mainly that ß after a short vowel became ss:
| Old spelling | Current spelling | Meaning |
|---|---|---|
| daß | dass | that (conjunction) |
| muß | muss | must |
| Fluß | Fluss | river |
| Schloß | Schloss | castle, lock |
| Kuß | Kuss | kiss |
You will still see the old forms in older books, on traditional shop signs and in some people’s handwriting. Words with a long vowel kept their ß: Straße, groß, Fuß were not affected.
The rule: ß after long vowels and diphthongs, ss after short vowels
The official rule says: for the voiceless s after a long vowel or diphthong, write ß, as long as no other consonant follows in the word stem. After a short vowel, write ss, just as German doubles other consonants after short vowels (Bett, Mitte, Fluss).
| Sound before the s | Spelling | Examples |
|---|---|---|
| Long vowel | ß | Straße, Fuß, groß, Gruß, süß, Maß, Spaß |
| Long ie | ß | gießen, schließen, fließen, Grieß |
| Diphthong (ei, ai, au, äu, eu) | ß | heißen, weiß, draußen, außen, beißen, Strauß |
| Short vowel | ss | Fluss, Kuss, muss, dass, Wasser, essen, besser |
The condition “no other consonant follows in the stem” explains words like Obst and Wüste: long vowel, but a t follows, so a single s. Endings do not count, which is why you write du heißt and am größten.
Why Haus but Fuß? A quick test
At the end of a word, the s sounds the same in Haus and Fuß. To decide, make a longer form of the word:
- Haus → Häuser: the s becomes voiced (a “z” sound), so write a single s.
- Fuß → Füße: the s stays voiceless after a long vowel, so write ß.
- Bus → Busse: short vowel, so the plural gets ss, while the singular keeps a single s (as do short words like das, was, bis).
The same works for Glas → Gläser (s) and Gruß → Grüße (ß). Words ending in -nis follow the Bus pattern: Ergebnis → Ergebnisse.
When the spelling changes inside a word family
Because the rule follows the vowel length, the spelling can switch between ß and ss within one family of words. This is where most mistakes happen.
| Stays the same | Switches between ß and ss |
|---|---|
| Fuß – Füße (long, always ß) | wissen – ich weiß – ich wusste |
| Fluss – Flüsse (short, always ss) | essen – ich aß – gegessen |
| Gruß – grüßen (long, always ß) | lassen – ich ließ – gelassen |
| Kuss – küssen (short, always ss) | schließen – ich schloss – geschlossen |
| groß – größer – am größten | fließen – es floss – der Fluss |
| Spaß – Späße | messen – ich maß – das Maß |
The official rules use exactly this kind of example: fließen, floss, Fluss, das Floß. Long vowel, ß. Short vowel, ss.
The capital ẞ: officially allowed since 2017
For a long time, ß had no capital. In texts written in capital letters, you wrote SS: STRASSE. In June 2017 the Council for German Orthography (Rat für deutsche Rechtschreibung) changed the official rules. They now say: in capital letters you write SS, and using the capital letter ẞ is also possible.
| Normal spelling | All caps (standard) | All caps (also allowed) |
|---|---|---|
| Straße | STRASSE | STRAẞE |
| Gießen | GIESSEN | GIEẞEN |
| Weiß (surname) | WEISS | WEIẞ |
The council pointed in particular to the correct spelling of names in passports and ID cards. The surnames Weiß and Weiss are different names, but in all caps with SS they look identical; WEIẞ keeps the difference. The 2024 edition of the official rules did not change this point. SS remains the standard and is never wrong. The capital has its own Unicode code point, U+1E9E.
Switzerland and Liechtenstein: always ss
The official rules allow Switzerland to always write ss, and Swiss schools, media and authorities do so: Strasse, gross, Fuss, heissen, Grüsse. Liechtenstein follows the Swiss practice. The usual explanation is historical: Swiss typewriters needed room for French and Italian letters such as é, à and ç, and ß was left off the keyboard.
If you write for Swiss readers, for example a job application in Zurich, use ss throughout. Mixing both systems in one text looks wrong in Germany and in Switzerland. More regional differences are in Swiss German vs Standard German. Austria writes ß like Germany, with a few word variants of its own (for example Geschoß, floor, alongside Geschoss, because many Austrians pronounce the o long); see Austrian German differences.
The rules also say: if ß is not available, write ss. That is the correct fallback, for example in email addresses or old systems.
Practise your German out loud with SipLingo, free to try on iPhone and Android:
How to type the German ß Eszett on any keyboard
| Device | How |
|---|---|
| German keyboard | Dedicated ß key, to the right of the 0 |
| Windows, any layout | Hold Alt and type 0223 on the numeric keypad |
| Windows, US-International layout | Right Alt + S |
| Mac (US or UK layout) | Option + S |
| iPhone and most Android keyboards | Long-press the S key |
| HTML | ß |
| Capital ẞ | Most keyboards have no key; copy it, or simply write SS |
If none of this works, write ss. Strasse is understood everywhere and is official in Switzerland.
ß is not β
The Greek letter β (beta) looks similar in some fonts, but it is a different letter. Straβe with a beta is a typo that sometimes appears on menus and signs abroad. Also avoid writing a capital B: StraBe is wrong too.
das or dass?
The most frequent ss word causes the most frequent spelling mistake. Dass is a conjunction (“that”) and sends the verb to the end: Ich weiß, dass du müde bist. Das is an article or pronoun: Das Buch, das ich lese, ist spannend.
Quick test: if you can replace the word with dieses or welches, write das. If not, write dass. Das as a relative pronoun is covered in German relative clauses, and the verb-final word order after dass in German word order rules.
How to pronounce ß
ß always sounds like a sharp, voiceless s. It matters because a single s between vowels is voiced in standard German, so ß and s can separate words:
| With s (voiced) | With ß (voiceless) |
|---|---|
| reisen (to travel) | reißen (to tear) |
| weise (wise) | weiße (white, as in die weiße Wand) |
And ß vs ss separates words by vowel length: in Maßen (in moderation, long a) vs in Massen (in huge amounts, short a), Buße (penance) vs Busse (buses). In southern Germany, Austria and Switzerland the single s is often voiceless too, so the reisen/reißen contrast is clearer in northern and standard pronunciation. The vowels themselves are explained in how to pronounce ä, ö, ü and ß.
Spelling rules are one half; the other half is saying the long and short vowels correctly. In SipLingo you speak in everyday scenarios and get a score for word accuracy and intonation, and you can tap any word to hear its pronunciation and translation. Practise your pronunciation in conversation.
20 common words with ß and ss
| Word | Meaning | Why |
|---|---|---|
| die Straße | street | long a |
| groß | big, tall | long o |
| heißen | to be called | diphthong ei |
| der Fuß | foot | long u |
| weiß | white / (I) know | diphthong ei |
| draußen | outside | diphthong au |
| die Grüße | greetings | long ü |
| süß | sweet | long ü |
| der Spaß | fun | long a |
| schließen | to close | long ie |
| außerdem | besides | diphthong au |
| bloß | only, merely | long o |
| der Fluss | river | short u |
| dass | that (conjunction) | short a |
| muss | must | short u |
| das Wasser | water | short a |
| essen | to eat | short e |
| besser | better | short e |
| die Adresse | address | short e |
| vergessen | to forget | short e |
One you will write all the time: Viele Grüße at the end of an email (in Switzerland: Viele Grüsse).
In short, the German ß Eszett comes down to one question: is the sound before it long (a long vowel or a diphthong) or short?
Rules checked in October 2026 against the official spelling rules of the Rat für deutsche Rechtschreibung (Amtliches Regelwerk) and the council’s 2017 press release on the capital ẞ.
Official sources
For the official details and the latest updates, see:
- Duden: Duden: s, ss and ß spelling rules – Official rule: ß after long vowels/diphthongs, ss after short vowels
Frequently asked questions
Do Germans still use ß?
Yes. ß is standard in Germany and Austria and is taught in every school. Only Switzerland and Liechtenstein write ss instead.
What is an Eszett?
The Eszett (ß), also called scharfes S, is a German letter for a voiceless s sound after a long vowel or diphthong, as in Straße or heißen. Its name comes from the letters s and z.
Is it ß or β?
Always ß. The Greek β (beta) only looks similar in some fonts and is wrong in German words: write Straße, not Straβe.
When do you use ß or ss (Wann schreibt man ß oder ss)?
Write ß after a long vowel or diphthong (Fuß, groß, heißen) and ss after a short vowel (Fluss, muss, dass). In all caps, write SS or, since 2017, the capital ẞ.
Why don’t the Swiss use ß?
Swiss spelling replaced ß with ss decades ago, and the official rules allow it. The usual explanation is that Swiss typewriters needed space for French and Italian letters.
Get the long and short vowels right when you speak. SipLingo scores your word accuracy and intonation in real conversations, with corrections in your own language.
