The quickest way to make text bigger on your iPhone

You can make text larger on your iPhone in two ways: change the size for all apps at once, or adjust it only in specific apps. The fastest method is to go to Settings > Display & Brightness > Text Size, then drag the slider to the right. This affects most built-in apps and many third-party ones when ready.

If that does not make text large enough, or if you want even bigger text in certain apps, your iPhone has a second option called Larger Accessibility Sizes. This lets you go much bigger, but you have to turn it on first in Settings > Accessibility > Display & Text Size, then toggle on Larger Accessibility Sizes. After that, the Text Size slider will extend further.

Key Takeaways

  • The Text Size slider in Display & Brightness is the standard way to enlarge text across most apps, and you can adjust it anytime without restarting your phone.
  • Larger Accessibility Sizes must be turned on in the Accessibility menu before the Text Size slider will go beyond its normal maximum.
  • Some apps like Messages, Mail, and Notes respond to both methods; others may only respond to one or may have their own separate text size controls.
  • If an app does not respond to system-wide text size changes, look inside that app's own settings menu for a text size or font option.

Using the standard Text Size slider

Open Settings on your home screen. Scroll down and tap Display & Brightness. You will see a slider labeled Text Size with an A on the left (smaller) and a larger A on the right (bigger). Drag the slider to the right to increase text size, or to the left to decrease it. The change takes effect when ready in most apps.

This method works in Mail, Messages, Notes, Reminders, Calendar, Stocks, and many third-party apps. Not every app respects this setting — some developers build their own text size controls instead. If you change the system text size and nothing happens in a particular app, that app likely has its own settings you need to adjust.

Enabling Larger Accessibility Sizes for maximum enlargement

If the standard Text Size slider does not go large enough, turn on Larger Accessibility Sizes first. Go to Settings > Accessibility > Display & Text Size. Toggle on Larger Accessibility Sizes. Your phone may take a moment to adjust.

Once you enable this, go back to Settings > Display & Brightness > Text Size. The slider now extends further to the right, letting you choose much larger sizes. This is useful if you have vision difficulties or straightforward prefer larger text. The trade-off is that very large text may not fit on a single line, so you will scroll more within apps.

Adjusting text size within individual apps

Some apps have their own text size controls that override or supplement the system setting. Open the app, look for a menu icon (often three horizontal lines or three dots), and search for options labeled Text Size, Font Size, Display, or Settings. Safari, for example, has its own text size control in the menu that appears when you tap the aA icon in the address bar.

If you use an app frequently and the system text size does not work well in it, spending a minute to find that app's own settings can save you frustration. Some reading apps like Kindle or Apple Books have extensive font controls, including font choice, line spacing, and margins — features the system text size cannot touch.

Bold text and other ways to improve readability

If larger text alone does not help, your iPhone has other readability features. Go to Settings > Accessibility > Display & Text Size and toggle on Bold Text. Your phone will restart, and all text will appear heavier and darker. This can make text easier to read without making it larger.

In the same menu, you can also turn on Increase Contrast to make text stand out more against backgrounds, or Reduce Transparency to remove blurred background effects that can make text harder to read. These work together — you can use bold text and larger text at the same time, or combine text size with increased contrast. Experiment to find what works best for you.

What to do if text size changes are not working

If you change the text size and nothing happens, first check whether the app has its own text size setting. Open the app, find its menu or settings, and look for font or display options. If the app has no such option, the developer may not have built text size support into that app.

If system text size is not working across multiple apps, restart your iPhone. Go to Settings > General > Shut Down, wait a few seconds, then press and hold the side button until the Apple logo appears. After your phone restarts, check whether text size changes now take effect. If the problem persists, you may need to update the app or iOS itself — go to Settings > General > Software Update to check for updates.

Frequently Asked Questions

Can I set different text sizes for different apps?

The system text size applies to all apps at once, but individual apps can override it with their own settings. If one app needs larger text than others, adjust the system size to a middle ground, then use that app's own text size control to go larger or smaller within it.

Will changing text size affect my battery life?

No. Text size changes do not use more or less battery. Bold text and increased contrast have no meaningful impact on battery either, though very high screen brightness does drain the battery faster.

What is the difference between Text Size and Larger Accessibility Sizes?

Text Size is the standard slider that works for most users. Larger Accessibility Sizes extends that slider much further, allowing text to grow to sizes designed for people with low vision. You only need Larger Accessibility Sizes if the regular Text Size slider does not go large enough.

Why does text size not change in some apps?

Some app developers build their own text size controls instead of using the system setting. Check the app's menu or settings for a font or display option. If none exists, the app may not support text size adjustment at all.

Can I make the keyboard text bigger too?

The system text size affects some keyboard text, but not all. If the keyboard is hard to read, go to Settings > Accessibility > Display & Text Size and enable Bold Text and Increase Contrast. Some keyboards also have their own size settings in their app-specific preferences.