The quickest way to change text size on your iPhone

Go to Settings > Display & Brightness > Text Size, then drag the slider left to make text smaller or right to make it larger. This change affects most built-in apps like Mail, Messages, Notes, and Calendar. The preview text at the top of the screen shows you what your choice will look like before you confirm it.

This slider works for apps made by Apple. Third-party apps like Facebook or Gmail may not respond to this setting — they often have their own text size controls buried in their individual settings menus.

Key Takeaways

  • The Text Size slider in Settings > Display & Brightness changes text across most Apple apps, and you see a preview before you save.
  • If regular text size adjustment is not enough, turn on Larger Accessibility Sizes to access even bigger options.
  • Bold Text in Settings > Accessibility > Display & Text Size makes all text on your phone heavier and easier to read, though it uses slightly more battery.
  • Third-party apps like Gmail or Instagram have their own text size controls that do not respond to your iPhone's main text size setting.
  • If you change your mind, you can return to the default size at any time — there is no penalty for adjusting multiple times.

Using Larger Accessibility Sizes for maximum text size

If the Text Size slider does not go large enough, turn on Larger Accessibility Sizes. Go to Settings > Accessibility > Display & Text Size > toggle on Larger Accessibility Sizes. Once you turn this on, the Text Size slider in Display & Brightness expands to show much larger options — up to sizes that would be difficult to read on purpose.

This setting is designed for people with low vision, but anyone can use it. The trade-off is that some apps may not display properly at the largest sizes — text might run off the edge of the screen or buttons might stack awkwardly. Test it in the apps you use most before committing to a very large size.

Making text bolder for easier reading

Turn on Bold Text to make every letter and number on your screen thicker and darker. Go to Settings > Accessibility > Display & Text Size > toggle on Bold Text. Your phone will restart after you turn this on. When it comes back, all text — in apps, menus, notifications, everything — will be heavier.

Bold Text works alongside your Text Size choice, so you can have both a larger size and bolder weight at the same time. The downside is that bold text uses slightly more battery power and can make some app layouts feel cramped. If you find it too heavy after a day or two, you can turn it off the same way you turned it on.

Changing text size in individual apps

Apps you read from the App Store often ignore your iPhone's text size setting and have their own controls. Open the app, look for a menu icon (usually three horizontal lines or three dots), and search for "Text Size", "Font Size", or "Display" settings. Gmail, for example, hides text size in Settings > Display options. Twitter has it under Settings and privacy > Display and sound.

If you cannot find a text size option in an app, that app may not offer one. In that case, your only option is to use your iPhone's zoom feature — pinch outward on the screen with two fingers to zoom in temporarily, though this zooms the whole screen, not just text.

Using zoom to enlarge everything on your screen

If you want to make everything bigger — text, buttons, images, all of it — use Zoom. Go to Settings > Accessibility > Zoom > toggle on Zoom. Once it is on, double-tap with two fingers anywhere on your screen to zoom in. Double-tap again to zoom back out. You can also pinch with two fingers to zoom in and out smoothly.

Zoom magnifies the entire screen, so it is useful when text size alone is not enough. The downside is that you can only see a portion of the screen at a time when zoomed in — you have to pan around to see the full picture. This works in all apps, including ones that do not respond to text size changes.

Checking which apps respond to your text size changes

Apple's built-in apps — Mail, Messages, Notes, Reminders, Calendar, Stocks, Weather, and News — all respond to your Text Size slider. Most third-party apps do not. The easiest way to know is to change your text size, then open the app and look. If the text did not change, that app has its own controls or does not offer text size adjustment at all.

If you use an app regularly and its text is too small, check its settings menu first. If there is no text size option there, contact the app maker through the App Store and ask them to add one. In the meantime, use your iPhone's zoom feature to enlarge that app's screen.

Resetting text size to the default

If you change your text size and want to go back to normal, open Settings > Display & Brightness > Text Size and drag the slider to the middle. The middle position is the default size. If you turned on Bold Text or Larger Accessibility Sizes and want to turn them off, go back to Settings > Accessibility > Display & Text Size and toggle them off.

There is no harm in changing these settings back and forth. You can adjust them as many times as you want, and your iPhone will not slow down or develop problems from doing so.

Frequently Asked Questions

Will changing text size affect my battery life?

Text size alone does not use more battery. Bold Text uses slightly more power because the screen has to work a bit harder to display thicker letters, but the difference is small — most people would not notice it. Zoom and Larger Accessibility Sizes do not affect battery either.

Can I set different text sizes for different apps?

No, the Text Size slider applies to all Apple apps at once. You can only control text size separately in third-party apps that have their own settings. If you need different sizes in different places, use Zoom to enlarge the screen temporarily when you need it.

Why is text in some apps still small even after I changed the setting?

That app either does not support the iPhone text size setting or has its own text size control. Check the app's settings menu for a text or display option. If there is none, the app maker has not built that feature in, and you will need to use Zoom to enlarge it.

Does text size change affect my home screen icons?

No. Text size changes only affect text inside apps and menus, not app icons on your home screen or the names below them. If you want to make icons bigger, you can use Zoom or rearrange your home screen to show fewer apps per row, which makes each one larger.