Where to find font settings on your iPhone
You can change the font size and style on your iPhone through the Settings app. The exact options depend on which version of iOS you have and what you want to change — whether that's the size of text in apps, the system font across your whole phone, or the font in specific apps like Mail or Notes.
Start by opening Settings and tapping Display & Brightness. This is where you'll find the most common font adjustment: text size. You'll see a slider with a small "A" on the left and a large "A" on the right. Drag the slider to make text larger or smaller across most apps on your phone.
If you want even larger text, go back to Settings, tap Accessibility, then Display & Text Size. Turn on Larger Accessibility Sizes. This unlocks even bigger text options than the standard Display & Brightness slider allows.
Key Takeaways
- Text size adjustments in Settings > Display & Brightness affect most apps on your iPhone, but not all apps respect this setting.
- Larger Accessibility Sizes in Settings > Accessibility > Display & Text Size provides the biggest text options available on iPhone.
- Bold text can be turned on in Settings > Accessibility > Display & Text Size to make fonts appear heavier and easier to read.
- Individual apps like Mail, Messages, and Notes may have their own font size controls separate from system-wide settings.
- iOS does not allow you to change the system font family itself — you can only adjust size, weight, and spacing.
Using Bold text for better readability
If you want text to appear thicker and darker across your phone, turn on Bold Text. Go to Settings, tap Accessibility, then Display & Text Size, and toggle on Bold Text. Your iPhone will restart, and when it comes back on, text throughout the system will appear bolder.
Bold text makes fonts easier to read, especially in low light or if you have vision difficulties. It affects system text, notifications, and most built-in apps. Some third-party apps may not respond to this setting, so you may still see regular-weight text in those places.
Adjusting letter spacing and line height
iOS also offers controls for spacing between letters and between lines of text. These are found in Settings > Accessibility > Display & Text Size. Look for Letter Spacing and Line Height — each has a slider you can adjust to make text less cramped or more spread out.
Increasing letter spacing makes individual letters easier to distinguish from one another. Increasing line height adds space between rows of text, which can help your eye track from one line to the next. These settings work together with text size and bold text to customize how readable your screen is.
Changing font size in specific apps
Some apps have their own font controls that override system settings. Mail, for example, lets you change text size within the app itself. Open Mail, go to Settings (inside the Mail app, not your phone's Settings), and look for a text size or font option.
Notes, Messages, and Safari also allow you to adjust text size within the app. In Safari, pinch the screen with two fingers to zoom in or out on a webpage — this is separate from your system font size. In Notes, you can select text and use the formatting menu to change size and style.
If an app doesn't have its own font controls, it will use whatever text size you set in your phone's Display & Brightness settings. Not all apps respect the system-wide text size slider, so you may find some apps with text that doesn't match your preference.
What you cannot change on iPhone
Apple does not allow you to change the system font family — the actual typeface — on iPhone. You cannot replace San Francisco (the default iPhone font) with Arial, Times New Roman, or any other font family. This is a limitation built into iOS and cannot be worked around through Settings.
Some apps, particularly those for reading or writing, may let you choose from a few font options within that app alone. But these changes only affect that one app and do not change the font elsewhere on your phone.
Troubleshooting font changes that don't stick
If you change your text size and it reverts back, check whether you have an app-specific setting overriding your system setting. Open the app, look for its own Settings or Preferences menu, and see if there is a font size control there. App-level settings usually take priority over system settings.
If text size changes are not working in a particular app at all, try closing the app completely and reopening it. Sometimes an app needs to restart to register a change to your system settings. If the problem persists, check the App Store to see if an update is available for that app.
Restart your iPhone if font changes are not working across multiple apps. Hold down the power button and volume button together, slide to power off, wait 10 seconds, then hold the power button again until you see the Apple logo. This often fixes settings that are not taking effect.
Frequently Asked Questions
Can I use custom fonts on my iPhone?
Third-party apps that focus on writing or design may let you install custom fonts for use within that app only. But you cannot change the system font that appears in Settings, Messages, Mail, or anywhere else on your home screen and throughout iOS. The system font is locked to San Francisco.
Will changing text size make my battery drain faster?
No. Text size changes do not affect battery life. Larger text uses the same amount of power as smaller text. If you notice your battery draining faster after a text size change, something else is likely the cause.
What is the difference between text size and Larger Accessibility Sizes?
The Display & Brightness text size slider goes up to a certain maximum. Larger Accessibility Sizes unlocks even bigger options beyond that maximum. If the standard slider is not large enough, Larger Accessibility Sizes will give you more extreme sizes to choose from.
Do font changes work in all apps?
Most built-in Apple apps and many third-party apps respect your system text size setting. However, some apps ignore it and use their own fixed text size. If an app does not respond to your system settings, check whether that app has its own font or text size control in its menu.
Can I change the font color on my iPhone?
You cannot change the color of system text across your whole phone. However, individual apps like Notes, Mail, and Messages may let you change text color within that app. Check the app's formatting or text options menu to see what color choices are available.