The quickest way to make text bigger or smaller
You can change the font size on your iPhone in two places: the Display & Text Size settings, which affects most apps, and the Accessibility settings, which lets you make text much larger if you need it. The Display & Text Size route is faster for small adjustments. The Accessibility route gives you more control and works in more places, including apps that ignore the standard setting.
Both methods take less than a minute. You do not need to restart your phone or close any apps — the change takes effect when ready in most places.
Key Takeaways
- Display & Text Size is the standard setting and affects Mail, Messages, Notes, and most built-in apps, but not all third-party apps.
- Larger Accessibility Sizes in Settings > Accessibility > Display & Text Size lets you go much bigger and works in more apps, including some that ignore the standard setting.
- Some apps have their own font size controls inside the app itself, separate from your iPhone settings.
- If text is still hard to read after you change the size, you can also turn on Bold Text or increase contrast in the same Accessibility menu.
How to change font size using Display & Text Size
Open Settings on your home screen. Tap Display & Text Size. You will see a slider at the bottom labeled with a small A on the left and a large A on the right. Drag the slider to the right to make text bigger, or to the left to make it smaller. The preview text above the slider shows you how your change will look.
This setting affects the default text size in Mail, Messages, Notes, Calendar, Reminders, and most other Apple apps. Some third-party apps built by other companies may not respond to this setting — those apps often have their own font size controls inside the app.
After you adjust the slider, tap the back arrow or swipe back to Settings. The change is live when ready.
How to use Larger Accessibility Sizes for bigger text
If the Display & Text Size slider does not go large enough, or if you want the text to be bigger in more apps, use the Larger Accessibility Sizes option. Open Settings, then go to Accessibility > Display & Text Size. Scroll down and toggle on Larger Accessibility Sizes.
Once you turn this on, the slider at the top of the same screen will expand to show much larger sizes. You can now drag it further to the right than before. This setting works in more apps than the standard Display & Text Size, including some third-party apps that would otherwise ignore the regular setting.
The trade-off is that some text may wrap differently or take up more screen space, so you might need to scroll more in some apps. But if readability is your priority, this is the most powerful option your iPhone offers.
Changing font size inside individual apps
Some apps have their own font size controls that override your iPhone settings. Mail, Books, and News are common examples. If you change your iPhone's font size but the text in a specific app does not change, look for a font or text size button inside that app.
In Mail, open an email and look for the three dots (more menu) in the top right corner. Tap it and look for an option like "Text Size" or "Display Settings". In Books, tap the middle of the page and look for the letter A with a plus or minus sign. In News, swipe up from the bottom of the article and look for text size controls.
These app-level controls usually override your system settings, so adjusting them will not affect other apps.
Making text easier to read beyond font size
If you have made the font larger but text is still hard to read, your iPhone has other tools in the same Accessibility menu. Bold Text makes every letter thicker and darker — open Settings > Accessibility > Display & Text Size and toggle on Bold Text. This works system-wide and takes effect after you restart your phone.
You can also increase contrast. In Settings > Accessibility > Display & Text Size, toggle on Increase Contrast. This makes the difference between text and background stronger, which helps if the text color is too close to the background color.
Both of these work together with your font size setting, so you can combine them if you need to.
Why some apps do not respond to your font size change
Third-party apps — apps made by companies other than Apple — are not required to follow your iPhone's font size setting. Some developers build their own text size controls into their apps instead. This is why you might change your iPhone's font size and see no change in, say, Twitter or Instagram.
If an app does not respond to your system font size, check inside the app for a settings or preferences menu. Look for options labeled "Text Size", "Font Size", "Display", or "Readability". Most popular apps have these controls somewhere, though the location varies.
If an app has no font size control and the text is too small, you can also use the Larger Accessibility Sizes setting described above — this works in more apps than the standard setting, though not all.
Checking whether your changes took effect
After you adjust your font size, open an app like Mail or Messages to see the change. The text should be noticeably different from before. If it is not, check whether you adjusted the slider far enough, or whether that particular app has its own font size control that is overriding your system setting.
If you turned on Larger Accessibility Sizes, remember that you need to restart your phone for Bold Text to take effect — but the font size change itself is when ready. For all other settings, the change happens right away without a restart.
Frequently Asked Questions
Can I set different font sizes for different apps?
No, your iPhone's system font size applies to all apps that follow it. However, apps with their own font size controls (like Mail or Books) let you override the system setting just for that app. So you could have a smaller font in Mail and a larger font in Messages if each app has its own control.
Will changing font size affect my battery life?
No. Font size is purely a display setting and does not change how much power your phone uses. Larger text does not drain your battery faster.
What is the difference between Display & Text Size and Larger Accessibility Sizes?
Display & Text Size is the standard setting and works in most Apple apps. Larger Accessibility Sizes goes much bigger and works in more apps, including some third-party apps. Use Larger Accessibility Sizes if the regular setting does not go large enough or if apps are ignoring your font size change.
If I change font size, will it affect text messages I receive?
Yes. Text messages in the Messages app will display in whatever font size you set. The person sending the message cannot control how large it appears on your phone — that is determined by your settings.
Can I undo a font size change?
Yes. Go back to Settings > Display & Text Size and move the slider back to where it was, or to the middle if you want the default size. There is no "reset" button, but the middle position is the standard size.