The infinity sign ∞ has no Windows Alt code, so copy it or type 221E then Alt+X in Word. On a Mac it is Option+5. John Wallis introduced it in 1655. It is not a number, so it cannot be added or divided like one.
01 All shortcuts at a glance
| Platform | Shortcut | |
|---|---|---|
| Windows (any app) | Win+. or Win+; emoji/symbol picker, or Character Map (Win+R → charmap) |
|
| Mac | Control+Command+Space to open Character Viewer, search "Infinity" |
|
| Word / Outlook | Type 221E, then press Alt+X |
|
| Linux (IBus) | Ctrl+Shift+U, then 221e, then Enter |
|
| HTML / CSS | ∞ · \221e (CSS) |
02 Step by step, per platform
A real, followable procedure for every platform, not a thin restatement of the shortcut.
Windows
- Open Character Map: Win+R, type charmap, press Enter.
- Search or scroll for Infinity (U+221E).
- Select it, click Copy, then paste where you need it.
Mac
- Press Control+Command+Space to open the Character Viewer.
- Type "Infinity" in the search field.
- Double-click the result to insert it.
Microsoft Word
- Type 221E.
- Press Alt+X immediately after, it converts the hex code to ∞.
03 Characters in this set
04 Troubleshooting & confusables
| Looks like it | But it's actually | When to use |
|---|---|---|
| 8 rotated | A digit turned on its side | Never. A rotated 8 will not copy, search or read out as infinity. |
| ∝ (U+221D) | Proportional to | A relation meaning one quantity scales with another. It is open on the right. |
| ♾ (U+267E) | Permanent paper sign, often shown as an emoji | A library standards mark. It is not the mathematical symbol. |
05 FAQ
What is the Unicode code point for the infinity sign?
It is U+221E, decimal 8734. There is no Windows Alt code for it.
How do I type it on a Mac?
Option+5 on a US layout. On Windows, type 221E and press Alt+X in Word, or copy the character.
Is infinity a number?
No. It is a concept describing unbounded growth, which is why ∞ minus ∞ is undefined rather than zero. Treating it as a value is the source of many false proofs.
Who invented the symbol?
The English mathematician John Wallis first used it in 1655. He never explained his choice, and the usual guesses are a variant Roman numeral for a thousand or the Greek letter omega.
What is the difference from the lemniscate?
The lemniscate is the geometric curve that gives the symbol its shape. In practice the words are used interchangeably, but only the character at U+221E means infinity in notation.