Change font size in Settings, not in individual apps
The main way to make text bigger or smaller across your iPhone is through the Display & Brightness settings. This changes the default text size for most built-in apps like Mail, Messages, Notes, and Safari. You adjust it in one place, and the change applies everywhere at once.
Some third-party apps (like Facebook or Instagram) ignore this system setting and have their own text size controls buried in their own settings. But for Apple's own apps and most others, the Display & Brightness method is where you start.
Key Takeaways
- Open Settings, tap Display & Brightness, then Text Size to adjust the default font size across most apps on your phone.
- If you need text even larger than the Text Size slider allows, turn on Larger Accessibility Sizes in Accessibility settings for much bigger options.
- Some apps like Safari let you pinch to zoom text temporarily, but this change only lasts while you're reading that page.
- Third-party apps often have their own text size settings that override the system default, so check inside the app itself if the system setting doesn't work.
- Bold text and high contrast options in Accessibility settings can make smaller text easier to read without making it larger.
How to adjust text size in Display & Brightness
Open the Settings app on your home screen. Scroll down and tap Display & Brightness. You'll see a section labeled "Text Size" with a slider underneath it — the slider shows a small "A" on the left and a large "A" on the right.
Drag the slider to the right to make text bigger, or to the left to make it smaller. As you move it, you'll see the sample text above the slider change size so you can see what you're choosing. When it looks right, let go of the slider. The change takes effect immediately in most apps.
This setting affects Mail, Messages, Notes, Reminders, Calendar, Stocks, Health, and many others. It does not affect text in Safari (Safari has its own zoom), text in your home screen app names, or text in apps that have overridden this setting with their own controls.
Make text much larger with Accessibility Sizes
If the Text Size slider doesn't go large enough, your iPhone has a second, more powerful option called Larger Accessibility Sizes. This gives you seven additional sizes beyond what the regular Text Size slider offers.
Open Settings and go to Accessibility. Tap Display & Text Size. Turn on the toggle next to "Larger Accessibility Sizes." Now go back to Display & Brightness and open Text Size again — the slider will now extend much further to the right, giving you much bigger options.
Be aware that Larger Accessibility Sizes can make some apps behave differently. Text might wrap onto more lines, buttons might move around, or some layouts might look cramped. But if you need significantly larger text, this is the way to get it.
Zoom text temporarily in Safari and Mail
In Safari, you can pinch the screen with two fingers to zoom in on a webpage, making the text larger. Pinch outward to zoom in, pinch inward to zoom out. This zoom only lasts while you're on that page — if you go to a different website or close Safari, the zoom resets.
Mail works the same way: pinch to zoom in on an email message to read it larger. This is useful when you need to read something once without changing your system-wide text size.
You can also double-tap a column of text in Safari to zoom in on just that column, which sometimes makes reading easier on a narrow phone screen.
Check individual apps for their own text size settings
Apps like Facebook, Instagram, Twitter, and many news apps don't use your system text size setting. Instead, they have their own text size controls hidden in their settings.
Open the app, look for a Settings or Preferences option (usually a gear icon or three horizontal lines), and search for "text size," "font size," or "display." The exact location varies by app, but most have something there. If you can't find it, try searching the app's help or support page for "text size."
If an app has no text size option at all, your only choice is to use Safari's pinch-to-zoom method if you're reading web content, or to use your iPhone's system-wide zoom feature (Settings > Accessibility > Zoom) to magnify the entire screen.
Use Bold Text and High Contrast to make small text easier to read
If you don't want to make text physically larger but need it to be easier to read, try turning on Bold Text. Open Settings, go to Accessibility, tap Display & Text Size, and turn on "Bold Text." Your phone will restart, and all text will appear thicker and darker, which makes it easier on the eyes without taking up more space.
You can also turn on "Increase Contrast" in the same menu. This makes text darker and backgrounds lighter, creating more separation between text and what's behind it. Some people find this combination — bold text plus high contrast — easier to read than simply making text larger.
These options work alongside your text size choice, so you can use them together. Bold text + larger text size + high contrast gives you the most readable setup if you're struggling with the default appearance.
What to do if text size won't change in a specific app
If you've adjusted your system text size but one particular app still shows tiny text, that app is overriding your setting. Your options are limited: either find that app's own text size control (check its settings menu), use pinch-to-zoom if the app supports it, or enable system-wide Zoom (Settings > Accessibility > Zoom) to magnify everything on screen.
System-wide Zoom magnifies your entire screen, not just text. You turn it on, then double-tap with three fingers to zoom in and out. It's slower than adjusting text size, but it works on every app including ones with no text size option.
If an app is completely broken and won't let you read anything, contact the app's developer through the App Store. They may have a newer version that respects your text size setting, or they may be able to tell you where their hidden text size control is.
Frequently Asked Questions
Will changing text size make my battery last longer or shorter?
Text size has no effect on battery life. Making text larger or smaller uses the same amount of power. If you're concerned about battery, focus on screen brightness and how long your screen stays on, not text size.
Can I set different text sizes for different apps?
No, the system text size setting applies to all apps that use it. If you need different sizes for different apps, you'll have to change the system setting each time you switch apps, or use each app's own text size control if it has one. Most people just pick one size that works for everything.
Does text size affect text messages I send to other people?
No. Your text size setting only changes how text appears on your own screen. The person receiving your message sees it in whatever size they have set on their phone. You're not sending them a larger or smaller message.
What's the difference between Text Size and Larger Accessibility Sizes?
Text Size is the standard slider with seven sizes. Larger Accessibility Sizes adds seven more sizes beyond that, for a total of fourteen options. Use Larger Accessibility Sizes if the regular Text Size slider doesn't go large enough for you.
If I turn on Bold Text, will it use more battery?
Bold Text uses slightly more power because the pixels have to work a bit harder to display thicker lines, but the difference is negligible. It won't noticeably affect your battery life.