The quickest way to make text bigger or smaller

You can change text size on your iPhone in two places: the Settings app controls the default size for most apps, and individual apps like Mail, Messages, and Safari have their own text size controls. The Settings method takes about 30 seconds and affects nearly everything you read on your phone.

Open Settings, tap Display & Brightness, then tap 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 where you want it, and the preview text below changes as you move it. That's the main adjustment most people need.

If you want text even larger than the Text Size slider allows, you can turn on Larger Accessibility Sizes in the same Settings menu. This unlocks even bigger options, though it may cause some text to wrap awkwardly in certain apps.

Key Takeaways

  • The Text Size slider in Settings > Display & Brightness controls default text size across most iPhone apps and system text.
  • Individual apps like Mail, Messages, Safari, and Notes have their own text size controls that override the system setting.
  • Larger Accessibility Sizes in Settings > Accessibility > Display & Text Size offers sizes beyond the standard slider range.
  • Some apps ignore the system text size setting entirely and require you to change text size within the app itself.

Changing text size in Settings for system-wide effect

The Settings method is the fastest way to make text bigger or smaller across your entire phone. Go to Settings > Display & Brightness > Text Size. The slider appears with a preview sentence that updates in real time as you move it. Slide left to make text smaller, right to make it larger. When you're satisfied, tap the back arrow or swipe back to exit.

This change affects Mail, Messages, Notes, Reminders, Calendar, Contacts, and most other built-in apps. It also affects system text like menu labels and button text. However, some third-party apps (like Facebook, Twitter, or news readers) may not respect this setting and will keep their own default size.

The Text Size slider has seven positions. If you find yourself always at the far right and still want larger text, that's when you move to Larger Accessibility Sizes instead of trying to push the slider further.

Using Larger Accessibility Sizes for maximum text enlargement

If the standard Text Size slider doesn't go large enough, your iPhone has a second tier called Larger Accessibility Sizes. Go to Settings > Accessibility > Display & Text Size > Larger Accessibility Sizes and toggle it on. This unlocks five additional sizes beyond the standard slider.

Once you turn on Larger Accessibility Sizes, go back to Settings > Display & Brightness > Text Size. The slider now extends further to the right, giving you 12 total size options instead of 7. The preview text shows you exactly how large your text will be before you confirm.

Be aware that very large text sizes can cause some apps to display text in unexpected ways—buttons may disappear off-screen, or text may wrap onto many lines. This is most common in older apps that weren't designed with accessibility in mind. If an app becomes hard to use at a larger size, you can adjust the text size within that specific app instead.

Changing text size in individual apps

Many iPhone apps let you override the system text size with their own controls. In Mail, open any email, tap the three dots at the bottom right, and select Aa. A menu appears with text size options (usually shown as small, medium, and large). In Messages, open a conversation, tap the contact name at the top, scroll down, and tap Text Size.

Safari has its own text size control. Open any webpage, tap the Aa icon in the address bar at the top, and use the plus and minus buttons to adjust. This setting sticks for that website, so the next time you visit, the text will be the same size you left it.

Notes, Reminders, and some other Apple apps also have text size controls buried in their menus or formatting options. If you can't find it, look for an Aa icon or a menu labeled "Text" or "Format." Third-party apps vary widely—some have text size controls in Settings, some in the app's own menu, and some don't offer the option at all.

Why some apps ignore your system text size setting

Your iPhone's system text size is a suggestion, not a requirement. Developers can choose to ignore it and set their own default text size instead. This happens most often with social media apps, news readers, and games, which may have their own design system that doesn't match Apple's standard.

If an app ignores your system text size setting, you have two options: change the text size within the app itself (if it offers that control), or contact the app's developer and ask them to respect the system setting. Some developers are responsive to this feedback, especially if many users request it.

Apple's own apps (Mail, Messages, Safari, Notes, Reminders, Calendar, Contacts) all respect the system text size setting. If you're using mostly Apple apps, the Settings > Display & Brightness > Text Size slider will handle most of your needs.

Combining text size with other display adjustments

Text size works alongside other display settings that can make reading easier. Bold Text, in Settings > Accessibility > Display & Text Size, makes all text thicker and darker. This can help readability even if you don't increase the size. Increase Contrast does something similar by making text stand out more against its background.

If you find yourself constantly adjusting text size in different apps, consider turning on Smart Invert or Classic Invert (Settings > Accessibility > Display & Text Size) to switch to a dark background with light text. Many people find this easier to read for long periods, especially in low light.

You can also reduce motion and transparency in the Accessibility menu, which can make the interface feel less cluttered and easier to focus on text. These settings work together—there's no single "best" combination, so experiment until reading feels comfortable for you.

What to do if text size changes aren't working

If you've adjusted the text size slider but nothing changed, the app you're using probably has its own text size control that overrides the system setting. Open the app's menu or settings and look for an Aa icon or text size option. Some apps also require you to close and reopen them after changing the system text size before the change takes effect.

If text size changes work in some apps but not others, that's normal—it means those apps don't respect the system setting. You'll need to adjust them individually. If text size isn't changing anywhere on your phone, restart your iPhone by holding the power button and swiping to power off, then turning it back on.

If you've turned on Larger Accessibility Sizes but the slider still doesn't go as large as you need, you've reached the maximum size your iPhone offers. At that point, your options are to use zoom (Settings > Accessibility > Zoom) to magnify the entire screen, or to look for apps designed specifically for low vision users.

Frequently Asked Questions

Does changing text size affect all apps on my iPhone?

No. Apple's built-in apps (Mail, Messages, Notes, Safari, Calendar, Reminders, Contacts) respect the system text size setting. Many third-party apps ignore it and use their own default size. You'll need to adjust text size within those apps individually if they offer that option.

Can I make text even bigger than the Larger Accessibility Sizes slider allows?

Yes. Turn on Zoom in Settings > Accessibility > Zoom, which magnifies your entire screen. You can pinch to zoom in and out on any screen, or set it to always zoom at a specific level. This works on top of text size adjustments.

Will changing text size make my battery drain faster?

No. Text size has no effect on battery life. Changing the brightness of your screen does affect battery, but text size itself does not.

What's the difference between Text Size and Larger Accessibility Sizes?

Text Size is the standard slider with seven sizes. Larger Accessibility Sizes unlocks five additional, much larger sizes beyond that. Most people use the standard Text Size slider; Larger Accessibility Sizes is for people who need significantly larger text.

If I change text size, will it change on my iPad or Mac too?

No. Text size settings are separate on each device. Your iPhone, iPad, and Mac all have their own text size controls, and changing one does not affect the others.