How to type I with Diaeresis
To type I with Diaeresis (ï), press Alt + 0239 on Windows, holding Alt while typing the digits on the numeric keypad, or press Option + U, I on Mac, or write ï in HTML. On any system you can copy it from this page, or enter its codepoint U+00EF directly: Ctrl+Shift+U then 00ef on Linux, or 00ef then Alt+X in Microsoft Word.
Latin Small Letter I With Diaeresis
- Copy it
- Unicode
- U+00EF
- Windows
- Alt + 0239
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 0239 | Hold Alt and type the number on the numeric keypad. |
| Mac | Option + U, I | Press the keys together. |
| HTML | ï | Paste this into HTML source. |
| Unicode | U+00EF | LATIN SMALL LETTER I WITH DIAERESIS |
Other accents symbols
ï lives in the Latin-1 Supplement block (U+0080-U+00FF), the accented letters and common signs Western European languages needed. Within Unicode it is classified as Ll, a lowercase letter. It has an uppercase counterpart and changes under case conversion. Its bidirectional class makes it left-to-right.
ï has a decomposed form: it can also be written as U+0069 Latin Small Letter I, U+0308 Combining Diaeresis. The two look identical and are not equal as strings, which is why a search for a word containing ï sometimes fails against text that was typed on a different system. Everything on this site uses the single-codepoint (NFC) form shown here.
Its uppercase counterpart is Ï (U+00CF). They are separate codepoints, so a byte comparison treats them as different characters even though a case-insensitive search does not.
Typing ï without switching keyboard
ï is the letter I carrying a diaeresis, and it is needed in French, Spanish and German. It is one character rather than two: a spell checker treats it as a letter of those alphabets, not as I with something added.
Both of the routes worth knowing compose the letter rather than looking it up. On a Mac press Option + U, let go, then press i: nothing appears until the second key, because the first one is a dead key waiting for a letter to sit under. On Windows the same idea needs the United States-International layout, which turns Shift + apostrophe into the same dead key. Add that layout once under Language and region, and ï costs two keystrokes from then on rather than four digits on a numeric keypad.
How I with Diaeresis behaves in software
ï takes one column in a terminal. It is a left-to-right character, so it holds that direction even inside a right-to-left paragraph.
Every way to write I with Diaeresis
| Form | Value |
|---|---|
| Codepoint | U+00EF |
| Decimal | 239 |
| UTF-8 bytes | C3 AF |
| UTF-16 bytes | 00 EF |
| HTML entity | ï |
| HTML numeric | ï or ï |
| CSS | \00EF |
| JavaScript | \u00EF |
| Python | \u00EF |
| URL-encoded | %C3%AF |
| SVG | 00EF.svg · (SIL Open Font License) |
If ï arrives as ï
That is this exact character, undamaged: its two UTF-8 bytes C3 AF are being read one at a time as Windows-1252. The Latin-1 range is where this happens most, because it is the range every legacy system thought it already handled. Nothing is lost, and retyping will not help: the fix is at the reading end, which has to be told the text is UTF-8. An empty rectangle is the opposite complaint, and means the encoding is right and the font has no glyph for U+00EF.