How to Change the Font Size on an iPhone

Improve text readability by altering size and other settings

Magnifying glass over a phone

 Rawpixel / Getty Images

by Heinz Tschabitscher
An independent writer who has reviewed hundreds of email programs and services since 1997.
Updated August 14, 2019

While you can zoom in on an email with finger gestures without adjusting the text size setting on your iPhone, iPad, or iPod touch, you'll need to zoom in on every app to increase the text size. However, you can change the size of text across every app at once using the slider in the Settings app. If you prefer a smaller text size that fits more content in a small screen, such as on an iPhone versus an iPad, move the slider to make the text size smaller.

Instructions in this article apply to devices running at least iOS 10, but may also work with older versions of iOS. The examples show an iPhone running iOS 12.

Dynamic Type and Text Sizes in Apps

Dynamic Type is the name of the iOS feature that adjusts the text size. Adjusting the size of the text isn't universal on an iOS device. Apps that support Dynamic Type take advantage of the customizable text sizes. Text in apps that don't support Dynamic Type will remain unchanged. Later versions of Apple apps support Dynamic Type, including Mail, Notes, Messages, and Calendar.

Accessibility settings can be used to further increase the font size and contrast.

How to Make the Font Bigger or Smaller

To use the Text Size option to adjust the font size on an iOS device:

  1. Open the Settings app.

  2. Go to Display & Brightness > Text Size. On versions of iOS older than iOS 11, go to General.


  3. Drag the slider right to increase the text size, or left to decrease the text size. The sample text changes as you adjust the text size.

    Display & Brightness, Text Size, slider in iOS Settings

On iOS 11 or newer, add the Text Size shortcut to Control Center for quicker access.

How to Make Text Even Larger

If these adjustments didn't make the text large enough, use the Accessibility settings to increase the text size. This adjustment forces even larger text in Mail and other apps that support Dynamic Type and is useful when it's difficult to read the text on a mobile device.

  1. Go to Settings > General > Accessibility.

  2. Tap Larger Text.

  3. Turn on the Larger Accessibility Sizes toggle switch.

    Accessibility, Larger Text, toggle in iOS Settings

  4. Drag the slider to the right to make the font larger.

Other Accessibility Features to Improve Readability

Also located from the Accessibility page in the device settings is Zoom. This magnifies the entire screen. Double-tap with three fingers to zoom, and drag three fingers to move around the screen.

Bold Text is another setting that makes it easier to read on an iPhone, iPad, or iPod touch. This setting makes Dynamic Type text bold.

Enable Increase Contrast to make other text styling adjustments, and Reduce Transparency to reduce transparency and blurs, both of which can increase legibility.