How to type the infinity symbol on iPhone
The standard iOS keyboard has no dedicated key for the infinity symbol on iPhone, but you can copy ∞ once and save it in Text Replacement with a shortcut like “inf”. Typing that shortcut instantly produces the infinity symbol on iPhone in any app.
Quick answer
Copy ∞ → Settings → General → Keyboard → Text Replacement → assign shortcut inf.
Step by step
Copy the infinity mark
Tap the Copy button at the top of this guide to place ∞ onto your iPhone clipboard.
Open iOS Text Replacement
Go to iPhone Settings → General → Keyboard → Text Replacement and tap the + icon in the upper-right corner.
Add your shortcut rule
Paste ∞ into the Phrase field, and type a quick abbreviation like inf or ;inf into the Shortcut field.
Type it anywhere on iOS
Type inf followed by a space in Messages, Notes, Safari, or social apps to insert ∞ automatically.
Why the iPhone keyboard omits ∞
The standard on-screen keyboard on iPhone and iPad includes common punctuation, numbers, and basic currency symbols, but leaves out advanced mathematical notation. The infinity symbol ∞ (the lemniscate, Unicode U+221E) does not appear on either the 123 or #+= keyboard screens, nor is it hidden behind any long-press key in standard English layouts. If you search the emoji keyboard, you may find the permanent infinity loop emoji ♾️, but it renders as a colorful or styled badge rather than clean, scalable mathematical text.
To write the authentic mathematical infinity sign ∞, copying it once and configuring an iOS Text Replacement provides the fastest and most elegant permanent solution. You can examine complete technical attributes, LaTeX codes, and entities on our infinity symbol page, and discover other mathematical operators in the math symbols collection.
Setting up the iOS Text Replacement
Setting up a text shortcut takes under thirty seconds. Launch the Settings app on your iPhone, navigate to General → Keyboard → Text Replacement, and tap the plus icon (+) in the upper right corner. Tap into the Phrase field and paste the copied ∞ character. In the Shortcut field, enter an abbreviation you can remember effortlessly, such as inf or ;inf.
Tap Save in the top corner. Because Apple syncs your keyboard shortcuts across your iCloud account, this shortcut will automatically become active on your iPad and Mac. Whenever you type your shortcut in Messages, Notes, Instagram captions, or browser text boxes, tapping the spacebar transforms your letters into ∞ instantly.
Typing ∞ with an external hardware keyboard
If you connect a physical keyboard—such as an Apple Magic Keyboard, Smart Keyboard Folio, or Bluetooth keyboard—to your iPad or iPhone, typing the infinity sign is even simpler. On the standard US hardware keyboard layout, pressing Option + 5 inserts the infinity symbol ∞ immediately in any application, requiring no text replacement at all.
Compare this process with our guides on the infinity symbol on Mac and infinity symbol on Windows, and learn Android alternatives in the infinity symbol on Android and how to type symbols on iPhone guides.
Frequently asked questions
Where is the infinity symbol on the iPhone keyboard?
The plain text infinity symbol ∞ is not on the standard keyboard. Copy it from this page and add it to Settings → General → Keyboard → Text Replacement.
Is there an infinity emoji on iPhone?
Yes. The emoji keyboard includes ♾️ (search “infinity”), but it appears as a purple or gray graphical badge rather than plain text ∞.
How do I type ∞ on iPad with a Magic Keyboard?
Press Option + 5 on a physical US keyboard attached to your iPad or iPhone to type the infinity symbol ∞ directly.