The simplest way to change font size on iPhone
Open Settings, tap Display & Brightness, then tap Text Size. Drag the slider left to make text smaller or right to make it larger. This change affects most built-in apps like Mail, Messages, and Notes when ready.
The text size slider works on a scale from smallest to largest. You will see a preview of how the change looks as you move the slider. Once you release it, the new size stays in place across your phone until you change it again.
Not all apps respect this setting. Some third-party apps like social media platforms have their own text size controls buried in their own settings, separate from the iPhone system setting. If an app's text does not change when you adjust the slider, you will need to look inside that app's settings menu instead.
Key Takeaways
- The Text Size slider in Settings > Display & Brightness is the main control and affects most built-in iPhone apps.
- Some third-party apps ignore the system text size setting and require you to change text size within the app itself.
- You can also turn on Larger Accessibility Sizes if you need text even bigger than the standard maximum.
- Safari and web pages may have separate zoom controls that work differently from the system text size setting.
Using Larger Accessibility Sizes for maximum text
If the Text Size slider does not 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.
Once you turn on Larger Accessibility Sizes, the Text Size slider expands to include much larger options. This setting is designed for people who need significantly bigger text and works across most system apps. The trade-off is that some apps may not display properly at these extreme sizes — buttons might move off-screen or text might overlap.
You can still use the regular Text Size slider even after turning on Larger Accessibility Sizes. The two settings work together: Larger Accessibility Sizes extends the range, and the slider lets you pick where in that extended range you want to be.
Changing text size in Safari and web browsers
Safari has its own text size control separate from the system setting. Open any webpage, tap the aA button in the address bar at the top, then tap the larger or smaller A to adjust just that page's text.
This change only affects the current webpage you are viewing. When you visit a different website, Safari will use its default text size unless you adjust it again. Some websites override Safari's text size setting with their own fixed sizes, so the aA button may have no visible effect on those pages.
If you want Safari to remember a text size preference across all websites, you can set a default in Safari settings. Go to Settings > Safari > Page Zoom and choose a percentage. This sets a baseline, but individual websites can still override it.
Changing text size in individual apps
Apps like Mail, Messages, and Notes usually respect the system Text Size setting, but some apps build their own controls. Open the app, look for a settings or gear icon, and search for options like "text size," "font size," or "display."
Social media apps like Facebook, Instagram, and Twitter often ignore the system setting entirely. You will need to go into each app's own settings to find text size controls. The location varies: some put it under "Display," others under "Accessibility," and some bury it under "Preferences."
If an app does not have a text size control and the system setting is not working, you have one more option: use the system-wide zoom feature. Go to Settings > Accessibility > Zoom and turn it on. This magnifies everything on your screen, not just text, but it works on any app.
Using system-wide zoom when text size is not enough
Zoom magnifies your entire screen, including text, buttons, and images. Turn it on in Settings > Accessibility > Zoom. Once enabled, double-tap with two fingers anywhere on the screen to zoom in and out.
Zoom is more powerful than text size adjustments because it works on every app, even ones that do not respect the system text size setting. The downside is that zooming magnifies everything, so you see less of the screen at once and have to scroll more to see the full picture.
You can adjust how much Zoom magnifies by going back to Settings > Accessibility > Zoom > Zoom Region. Choose between Full Screen Zoom (magnifies everything) or Window Zoom (magnifies only a floating window). Window Zoom lets you see both the zoomed area and the normal screen at the same time.
Changing font size on your iPhone keyboard
The iPhone keyboard itself does not have a separate text size setting. The keyboard text size follows the system Text Size setting you chose in Display & Brightness. If the keyboard text looks too small or too large, adjust the main Text Size slider and the keyboard will change along with it.
If the keyboard is hard to read but you do not want to change text size everywhere else on your phone, consider using the system-wide Zoom feature instead. Zoom in when you are typing, then zoom back out when you are done.
What happens when you change text size
Changing the Text Size slider affects most of Apple's built-in apps right away: Mail, Messages, Notes, Reminders, Calendar, and the Settings app itself all respond to the change. You do not need to close and reopen these apps — the text size updates when ready.
Third-party apps are unpredictable. Some respect the system setting, some ignore it, and some partially respect it. There is no way to know until you try. If an app's text does not change when you adjust the slider, that app has its own text size control or does not support the system setting at all.
Text size changes do not affect your phone's performance or battery life. You can change the setting as many times as you want without any negative effects. Some people adjust text size depending on the time of day or their lighting conditions.
Frequently Asked Questions
Why did my text size change back to the default?
Text size does not reset on its own unless you restart your phone or update iOS. If it changed unexpectedly, check whether a specific app has its own text size setting that overrode the system setting. Some apps also reset their preferences after an update.
Can I set different text sizes for different apps?
No, the system Text Size setting applies to all apps that respect it. However, apps with their own text size controls let you set a different size just for that app. You can also use Zoom to magnify only when you need it, leaving other apps at normal size.
Does changing text size affect how much storage my phone uses?
No. Text size is just a display setting and does not change how much space anything takes up on your phone. It only changes how large the text appears on your screen.
What if text is still too small even at the largest setting?
Turn on Larger Accessibility Sizes in Settings > Accessibility > Display & Text Size to unlock even bigger sizes. If that is still not enough, use the Zoom feature to magnify your entire screen. You can also combine both: turn on Larger Accessibility Sizes and then use Zoom on top of it.
Does changing text size on iPhone affect text on my other Apple devices?
No. Text size is a per-device setting. Your iPad, Mac, and Apple Watch all have their own separate text size controls. Changing one device does not change the others.