Ä and ä: the A with Umlaut, Its ae Fallback and Danish æ

Is ä a separate letter or an a with an umlaut?

Whether the a with umlaut is a letter depends on the alphabet. Swedish, Finnish, Estonian and Slovak count ä as a letter with its own name and place. German calls it an umlaut letter. The Amtliches Regelwerk (opens in a new tab), the official German spelling rules, lists ä, ö and ü after z. It files them together with a, o and u.

Language	What ä is	Its name or place	How the letter sounds	A word with it
German	an umlaut letter, filed with a	after z in the list, sorted as a	short /ɛ/ or long /ɛː/	Bär, bear: /bɛːr/
Swedish	a letter	second to last, between å and ö	/æː/ as a name, /ɛː/ in many words	bär, berry: /bɛːr/
Finnish	a letter, named ää	after å, before ö	/æ/	päivä, day: /ˈpæi̯ʋæ/
Estonian	a letter, named ää	among õ, ä, ö, ü, just before x	/æ/	päev, day: /ˈpæe̯v/
Slovak	a letter, named široké e	right after a and á	usually said as e	mäso, meat: /mæsɔ/, [ˈmesɔ]

The sounds and words come from Wiktionary's entries for ä (opens in a new tab), Bär (opens in a new tab), bär (opens in a new tab), päivä (opens in a new tab), päev (opens in a new tab) and mäso (opens in a new tab). The Estonian place follows the Estonian collation rules (opens in a new tab) in Unicode CLDR.

The German and Swedish words look identical, yet a German Bär is an animal and a Swedish bär is fruit. The status matters for more than sorting. Where ä is a letter, a with dots and plain a spell different words. A missing dot is a typo. In German, ä is tied to a, and the spelling often shows it: Kälte, cold, comes from kalt.

When is ae an accepted spelling of ä?

In German, ae is the usual stand-in for an a with umlaut that cannot be typed. Finnish and Swedish drop the dots instead, so the a umlaut becomes a plain a. Oddly, the official German rules say nothing about ae. The Regelwerk gives a fallback for ß, which becomes ss in § 25 E2, and none for the umlaut letters.

The ae habit is written down in other places: in ICAO Doc 9303 (opens in a new tab) for passports and in the German CLDR collation (opens in a new tab) for phone books.

Where ä cannot be written	What replaces it	Who says so
A passport's machine-readable line	AE or A	ICAO Doc 9303, Part 3, section 6.A
A German phone book or name list	ä is sorted as ae	the phonebook order in the German CLDR collation
Finnish text on a system without ä	a, not ae	Wiktionary's usage note on Finnish ä
A web address in Finland or Sweden	a	the cities' own addresses, below
A web address in Germany	ae	the cities' own addresses, below

The table of city web addresses shows the split in practice. We opened each official address and then typed the same name with its ä, on 2026-10-09. The official sites are linked in the sources at the end of the page.

Place	Official address	Typed with ä	What answered
Jyväskylä, Finland	jyvaskyla.fi	jyväskylä.fi	a redirect to jyvaskyla.fi
Hämeenlinna, Finland	hameenlinna.fi	hämeenlinna.fi	a redirect to hameenlinna.fi
Västerås, Sweden	vasteras.se	västerås.se	a redirect to vasteras.se
Växjö, Sweden	vaxjo.se	växjö.se	a redirect to vaxjo.se
Bad Säckingen, Germany	bad-saeckingen.de	bad-säckingen.de	no such domain
Märkischer Kreis, Germany	maerkischer-kreis.de	märkischer-kreis.de	no such domain

The pattern matches the table above it. The Finnish and Swedish names lose their dots, and the German names spell the umlaut as ae. Search rules agree. In the Node.js check described further down, German rules match maedchen to Mädchen. Finnish rules match neither jyvaskyla nor jyvaeskylae to Jyväskylä.

Going back from ae to ä is not safe. Many German words have a and e side by side as two vowels. Wiktionary transcribes Michael (opens in a new tab) as /ˈmɪçaˌeːl/ and Israel (opens in a new tab) as [ˈiːsʁaʔeːl], with a break between the a and the e. A script that turns every ae into ä would print Michäl. Fix such text by hand or against a word list.

How do Germans choose between ä and e?

German writes the a with umlaut for the e sound when a related word has a. This is § 13 of the Regelwerk: Bänder because of Band, Hälse because of Hals, Kälte because of kalt. Wiktionary gives Kälte (opens in a new tab) as /ˈkɛltə/, an ordinary short e sound. The ear cannot choose the letter, so the base word decides.

The rule also explains why some German words sound alike and are spelled apart. The Regelwerk lists such pairs. Wiktionary's entries for Lärche (opens in a new tab), Lerche (opens in a new tab), Ähre (opens in a new tab) and Ehre (opens in a new tab) show how close they are.

With ä	With e	Wiktionary IPA	Meanings
Lärche	Lerche	both /ˈlɛʁçə/	larch, the tree; lark, the bird
Ähre	Ehre	/ˈɛːrə/, for many speakers [ˈʔeː.ʁə]; /ˈeːʁə/	ear of grain; honour

The Regelwerk adds Äsche and Esche, and Färse and Ferse, to the same list. It notes that long [eː] and long [ɛː] are often not told apart in speech. The facts on this page agree: WikiPron writes wäre as /veːʁə/, with [eː] rather than [ɛː].

Some words break the rule, and § 14 and § 15 name them. The words ätzen, dämmern, Geländer, Lärm, März and Schärpe take ä with no a-word behind them. Eltern keeps its e despite alt, and schwenken despite schwanken. So a blind swap of ä for e, or e for ä, breaks real words in both directions.

Is ä the same letter as Danish and Norwegian æ?

No. The a with umlaut and æ are close relatives, not one letter. Danish and Norwegian write æ where Swedish and German write ä. Wiktionary's Norwegian entry for æ (opens in a new tab) calls ä the corresponding letter. Both began as a and e. Wiktionary says Swedish ä started as a ligature of A and E. Later it was an a with a small e on top, and the dots came in the early 18th century.

As characters, the two have nothing in common. UnicodeData.txt (opens in a new tab) breaks ä down into a plus the combining diaeresis, U+0308. The æ, LATIN SMALL LETTER AE, has no breakdown at all.

	ä	æ
Unicode name	LATIN SMALL LETTER A WITH DIAERESIS	LATIN SMALL LETTER AE
Breaks down into	a + U+0308	nothing
Alphabets that use it, per CLDR	Swedish, Finnish, Estonian, German, Slovak, among others	Danish, Norwegian, Faroese, Icelandic, among others
The word for berry	Swedish bär, /bɛːr/	Danish bær, /bɛr/; Norwegian Nynorsk bær, /bæːr/
How Nordic sorting treats the other letter	Swedish and Finnish file æ as ä	Danish files ä as æ
In a passport's machine-readable line	AE or A	AE

The berry row comes from Wiktionary's bär (opens in a new tab) and bær (opens in a new tab). The sorting row comes from the CLDR rules for Swedish (opens in a new tab), Finnish (opens in a new tab) and Danish (opens in a new tab). We checked it with the locale-aware compare in Node.js v26, which runs ICU 78.3 on CLDR 48 data. Under Danish, Swedish and Finnish rules, a search for Lærke finds Lärke. Under English rules it does not.

One alphabet breaks the family likeness. In Icelandic, æ is not a front a at all: Wiktionary gives the letter's name as [ˈaiː], a diphthong. So an Icelandic æ should not be rewritten as ä.

Why does Slovak write ä only after p, b, m and v?

Slovak allows the a with umlaut only after p, b, m and v because its spelling rules limit it there. The Pravidlá slovenského pravopisu (opens in a new tab) are the rules of the Ľudovít Štúr Institute of Linguistics. They put ä mostly in word roots, more rarely in endings, and never in a prefix. It is also the only Slovak letter whose mark is two dots.

After	Words the rules list with ä
p	päť (five), päta, opäť, späť
b	bäkať, and the ending of žriebä
m	mäso (meat), mäkký, pamäť, najmä, Demänová
v	väčší, svätý, deväť, zväz

In everyday standard Slovak, ä is not heard as a vowel of its own. The rules say neutral standard speech replaces it with a plain e, and they keep the spelling anyway. Wiktionary records both: it lists päť (opens in a new tab) as /pæc/ and also as [ˈpec].

ä has no long partner in Slovak. Where other vowels have a long form with an acute, ä has only the diphthong ia. Names keep it too: Svätopluk is among the given names in the facts below.