Mathematical symbol Infinity
About this character
The character ∞ carries the official Unicode name “Mathematical symbol Infinity” and the code point U+221E, which is 8734 in decimal. It belongs to the Mathematical Operators block (U+2200–U+22FF), which gathers the operators, quantifiers and relations of algebra, logic and set theory.
In memory, ∞ takes 3 bytes in UTF-8 (0xE2 0x88 0x9E) and 1 in UTF-16 (0x221E). That difference is why badly configured forms or databases garble this character: they assume one byte per character.
How to type ∞
| System | What to do |
|---|---|
| Windows | In Word or WordPad, type 221E and press Alt + X to turn the code into the character. |
| macOS | On a Mac using the ABC/US layout, ⌥ + 5 produces this character directly. |
| Linux | On Linux (GTK), type Ctrl + ⇧ + U, 221E then press Enter. |
| HTML / Web | In an HTML page, write ∞. Use \221E in CSS, \u221E in JavaScript and \u221E in Python. |
| On this site | The simplest route is the Copy button above: the character goes straight to your clipboard, ready to paste anywhere. |
Keyboards that include ∞
This character is not on any common physical layout, so the Copy button above is the quickest way to get it into a document.
Codes and encodings
| Property | Value |
|---|---|
| Code point | U+221E |
| Unicode block | Mathematical Operators (U+2200–U+22FF) |
| Decimal | 8734 |
| Hexadecimal | 0x221E |
| Octal | 021036 |
| Binary | 10001000011110 |
| UTF-8 bytes | 0xE2 0x88 0x9E |
| UTF-16 units | 0x221E |
| Named HTML entity | ∞ |
| Decimal HTML entity | ∞ |
| Hex HTML entity | ∞ |
| CSS escape | \221E |
| JavaScript escape | \u221E |
| Python escape | \u221E |
| URL encoding | %E2%88%9E |
Frequently asked questions
What is the Unicode code for ∞?
Its code point is U+221E, which is 8734 in decimal and 021036 in octal. In HTML you can write it as ∞ or ∞.
Why does ∞ show up as a box or a question mark?
An empty box means the font has no glyph for U+221E. The character is still in the text: switching to a font that covers the block (Noto, DejaVu or Segoe UI Symbol) makes it appear.
Can I use ∞ in a filename, a URL or a password?
In a URL it must be encoded as %E2%88%9E. Modern filesystems accept it, though it is still risky when moving files between systems. For passwords, some forms reject non-ASCII characters outright.