Typing þ, ð, æ, ö and the Accents

Icelandic uses ten letters your English keyboard does not have a key for: the consonants þ (thorn) and ð (eth), the vowels æ and ö, and the six acute-accented vowels á é í ó ú ý. Typing them is not optional decoration — these are full letters of the alphabet, and leaving them off produces misspelled words, sometimes entirely different words. This page is a hands-on reference for producing all of them, in upper and lower case, on the systems you are likely to use. (For where these letters sit in the alphabet and how they sort, see writing/alphabet; for how þ and ð are pronounced, see pronunciation/thorn-eth.)

The fastest fix: install the Icelandic keyboard

If you will type Icelandic regularly, the single best move is to add the Icelandic keyboard layout to your system. Every special letter then gets a real key, and you stop fighting modifier combinations.

• macOS: System Settings → Keyboard → Text Input → Edit → add Icelandic, then switch with Control+Space (or Cmd+Space). On the Icelandic layout, ð sits on the [ key, þ on the / key, æ and ö are along the right side, and a dead-key acute lives on the apostrophe key — press it, then a vowel, to get the accent.
• Windows: Settings → Time & Language → Language & region → add Icelandic (or just its keyboard) → switch with Win+Space.
• Linux: Settings → Keyboard → add the Icelandic input source.

macOS without switching layouts (US Extended)

If you don't want to switch keyboards, the US Extended ("ABC – Extended") layout lets you type the Icelandic letters from a normal US keyboard using the Option key. Add it the same way as above.

• þ — Option+t
• ð — Option+d
• æ — Option+' (apostrophe)
• ö — Option+u, then o (the Option+u "dead key" puts an umlaut/diaeresis on the next vowel)
• The acute accents — Option+e, then the vowel. So Option+e then a → á; Option+e then o → ó; Option+e then y → ý.

For uppercase, add Shift: Þ is Option+t while holding Shift (or Shift+Option+t), and Á is Option+e then Shift+a.

Windows Alt codes

On Windows with a numeric keypad, hold Alt, type the four-digit code on the keypad (Num Lock on), and release. The codes for the Icelandic letters:

The two you will reach for constantly are þ (Alt+0254) and ð (Alt+0240) — worth committing to memory. If your laptop has no numeric keypad, the Alt-code method is awkward; switch to the Icelandic layout instead.

Mobile (iOS and Android)

On phones, the trick is the long-press. Hold down the base letter and a small menu of variants pops up; slide to the one you want.

• Long-press a → choose á or æ
• Long-press o → choose ó or ö
• Long-press d → choose ð
• Long-press t → choose þ
• Long-press e / i / u / y → choose é / í / ú / ý

Even simpler: add the Icelandic keyboard in your phone's keyboard settings, which surfaces all ten letters directly. Both iOS and Android support it.

The all-in-one reference table

HTML and Unicode fallbacks

When you cannot type the letter directly — in code, a constrained form field, or markup — use the HTML entity or the Unicode code point:

The vowels é í ó ú follow the same pattern (é, í, ó, ú), and ý is ý (or the numeric form ý, U+00FD).

ð and þ are different letters — don't swap them

A trap specific to these two: ð (eth) and þ (thorn) are separate letters with separate keys and separate jobs, not two styles of the same sound. Thorn þ only ever begins a word (or syllable) and is voiceless, like English "th" in thing. Eth ð never begins a word; it appears in the middle or at the end and is voiced, like the "th" in this. Typing one for the other is a spelling error, the same as swapping "p" and "b."

And ö is its own vowel, not "o with an umlaut" in any conceptual sense — it is the fifteenth-ish letter of the Icelandic alphabet, with its own sound and its own place. Treating it as a decorated "o" leads to dropping it ("o" or "oe"), which is wrong.

Never drop the acute accents

The acute (called broddur in Icelandic) is part of the spelling, not an optional stress mark. Dropping it does not give a "plainer" version of the word — it gives a different word or a non-word:

So á, sá, frí are genuinely distinct from any accent-less spelling. Treat the broddur the way you treat the dot on an "i": leave it off and you have misspelled the word.

Common Mistakes

Key Takeaways

• Icelandic needs ten extra letters: þ ð æ ö and á é í ó ú ý — all real letters, not optional marks.
• The most robust solution is to install the Icelandic keyboard layout; on macOS, US Extended gives Option+t → þ, Option+d → ð, and Option+e + vowel → the acute.
• On Windows, the everyday codes are Alt+0254 (þ) and Alt+0240 (ð); on mobile, long-press the base letter.
• Use HTML entities (þ, ð, æ, ö) or Unicode code points when you cannot type directly.
• ð and þ are distinct letters (eth inside/end, thorn at the start), ö is its own vowel (not o-umlaut), and the acute accents are never optional — án ≠ an, sá ≠ sa, frí ≠ fri.

Sources:

• Alt Codes for Icelandic Letters with Accents (altcodeunicode.com)
• ALT Codes for Windows – Penn State Symbol Codes
• Icelandic characters – Apple Community