Where to find font settings on your iPhone
Font changes on iPhone happen in two places: Settings for system-wide text size, and individual apps for their own fonts. Most readers want to make text bigger everywhere at once, which you do through Settings > Accessibility > Display & Text Size. That controls the size of menus, notifications, email, messages, and most built-in apps.
Some apps — like Notes, Mail, and Books — also let you change fonts within the app itself. Those changes affect only that app and override the system setting. If you change the system font size first and then adjust an app's font separately, the app setting wins.
Key Takeaways
- System-wide text size lives in Settings > Accessibility > Display & Text Size, and affects menus, email, messages, and most apps at once.
- Larger Accessibility Sizes (the slider at the bottom) make text bigger than the standard maximum, but only in apps that support them.
- Individual apps like Mail, Notes, and Books have their own font menus inside the app, separate from the system setting.
- Bold text, high contrast, and reduce transparency are separate toggles in the same Accessibility menu and work alongside font size changes.
How to increase text size system-wide
Open Settings and tap Accessibility. Then tap Display & Text Size. You will see a slider labeled "Text Size" with a small "A" on the left and a large "A" on the right. Drag the slider to the right to make text larger. This affects Settings menus, Mail, Messages, Calendar, Reminders, Stocks, and most other built-in apps.
Below that slider is another option called "Larger Accessibility Sizes." Toggle it on, and a second slider appears. This one goes much larger than the first and is meant for people who need significantly bigger text. Not all apps support Larger Accessibility Sizes — some third-party apps ignore it — but all Apple apps do. Check the app itself to see if it responds.
Changing fonts in Mail, Notes, and Books
Mail and Notes let you pick a different typeface. In Mail, open an email you are composing, tap the formatting icon (looks like "Aa"), and select a font from the menu. In Notes, start a new note, tap the formatting icon, and choose from the available fonts. These changes explore only to that note or email, not to all your notes or all your mail.
Books has its own font menu. Open a book, tap the text size icon (usually at the top of the page), and you will see font options. Some books lock you into the publisher's chosen font, so the menu may be grayed out. Mail and Notes always let you choose.
Making text bolder and easier to read
If larger text alone is not enough, Settings > Accessibility > Display & Text Size also has toggles for Bold Text and High Contrast. Bold Text makes all system text thicker. High Contrast increases the darkness of text against its background. Both work alongside the text size slider and can be turned on or off independently.
Another useful toggle in the same menu is Reduce Transparency. This removes the frosted-glass effect from menus and makes backgrounds more solid, which some people find easier to read. All three of these settings work together — you can turn on Bold Text and High Contrast at the same time, for example.
What happens when apps ignore your font size
Some third-party apps do not respect your system text size setting. They use their own internal font size and ignore what you set in Accessibility. You have a few options: check the app's own settings menu (usually under a gear icon or "Preferences"), contact the app maker to request the feature, or use the app's zoom function if it has one.
If an app is critical and does not support text size changes, you can zoom the entire screen using Settings > Accessibility > Zoom. This magnifies everything on the screen, but it is slower to navigate because you have to pan around. It is a last resort, not a daily solution.
Using Dynamic Type for consistent sizing across apps
Apple calls its system-wide text sizing "Dynamic Type." When you change the text size in Settings, any app that supports Dynamic Type automatically adjusts. Most Apple apps and many popular third-party apps (like Twitter, Reddit, and Slack) support it. Apps that do not support it show the same size no matter what you set in Accessibility.
You can check whether an app supports Dynamic Type by opening it and changing your system text size, then going back to the app. If the text got bigger, it supports Dynamic Type. If it stayed the same, it does not. There is no master list — you have to test each app.
Frequently Asked Questions
Can I change the font on my lock screen?
No. The lock screen uses a fixed font that you cannot change. You can change the text size of notifications on the lock screen through Settings > Notifications, but the typeface itself is locked. The system font on menus and settings can be made larger through Accessibility, but not changed to a different style.
Why does my text size reset after I restart my iPhone?
It should not. Text size settings in Accessibility are saved and persist through restarts. If your text size keeps resetting, restart your iPhone again (Settings > General > Shut Down, then turn it back on). If it still resets, back up your iPhone and restore it from backup in Settings > General > Transfer or Reset.
Does changing font size affect battery life?
No. Text size has no measurable effect on battery. Bold Text and High Contrast also do not drain the battery. Reduce Transparency might save a tiny amount of power on older iPhones because it removes animation, but the difference is negligible on current models.
Can I use a custom font I downloaded?
Not system-wide. You cannot install custom fonts for use in Settings, Mail, or Messages. Some apps like Notes and Pages let you install fonts through their own menus, but those fonts work only inside that app. To use a custom font system-wide, you would need to jailbreak your iPhone, which voids your warranty and is not recommended.
What is the difference between text size and bold text?
Text size makes letters taller and wider. Bold Text makes them thicker and darker without changing their height. You can use both at the same time. Bold Text is useful if you have trouble seeing thin strokes; text size is useful if you need letters to be physically larger on the screen.