Quick answer
Copy ∞ above. On a U.S. Mac keyboard, press Option + 5. In Microsoft Word, type 221E and press Alt + X. On Windows elsewhere, use Character Map or the symbol panel.
Infinity-symbol methods
The infinity symbol resembles a sideways figure eight. It appears in mathematics, science, engineering, philosophy, and decorative text. Use the actual character ∞ when plain Unicode text is appropriate.
| Platform | Method |
|---|---|
| Mac (U.S.) | Option + 5 |
| Microsoft Word | Type 221E, then Alt + X |
| Windows | Character Map or the symbol panel |
| Google Docs | Insert → Symbols → Special characters → search “infinity” |
| HTML | ∞ or ∞ |
Type ∞ in Windows
Windows does not provide a simple, classic Alt code for the infinity sign that behaves consistently in every application. Press Windows + . and look in Symbols, or open Character Map, select ∞, and copy it.
If you are working in Word, the Unicode conversion is faster: type 221E, then press Alt + X. The code becomes ∞. For technical documents, the equation editor may be better because it understands mathematical structure as well as appearance.
Type ∞ on a Mac
On the U.S. keyboard layout, press Option + 5. If that gives a different character, open Character Viewer with Control + Command + Space, search “infinity,” and insert it. Keyboard shortcuts can vary with the active input source.
Add infinity in Docs, Slides, and spreadsheets
In Google Docs or Slides, choose Insert → Symbols → Special characters and search for “infinity.” You can also draw the symbol in the search area when you do not know its name.
For Excel and Google Sheets, paste ∞ into a label. Do not substitute it for a numeric value in a calculation unless your formula or software explicitly supports that meaning. A cell containing the glyph is text, not an unlimited numeric value.
Infinity in equations
When writing limits, intervals, or formal notation, use an equation editor or accessible math format such as MathML or LaTeX. A standalone Unicode character looks correct in simple prose, but an equation needs relationships, superscripts, subscripts, and reading order that plain text may not capture.
For example, interval notation often uses (-∞, ∞). The infinity character is part of the notation, but the complete mathematical meaning comes from the surrounding brackets and context.
Use ∞ on a web page
UTF-8 HTML supports the literal character. The named entity is ∞; decimal is ∞; hexadecimal is ∞. A modern system font should include it.
If the symbol is part of meaningful math, do not place it only in a background image. Keep an accessible text or MathML representation so it can be copied and interpreted by assistive technology.
Similar characters
The proportional-to sign ∝, looped decorative icons, and a sideways “8” image are not the same Unicode character. They can look similar in a stylized font but have different names and meanings. The infinity sign is U+221E.
Troubleshooting
If the symbol appears as a box, switch to a font with broad mathematical coverage. If an export replaces it with ?, save the file as UTF-8. If an app interprets 221E as ordinary text, remember that Alt + X is a Word feature rather than a universal Windows command.
References and compatibility
These platform references explain the input methods used above. Availability varies by app and keyboard layout; a Unicode value is not automatically a numeric-keypad Alt code.
Editorial note: Shortcuts can vary by keyboard layout and app. Check the stated platform and use the copy-and-paste fallback when needed. Report a correction with your device, layout, and application; see our editorial policy for limitations.