Half the support calls I get from new iPhone users start with: "I made the text bigger but Safari is still tiny." Apple has three different text-size settings that each affect different apps, and there is a hidden fourth one most users never find. Here is how they fit together.

Why there are three settings, not one

Apple separated text size into three settings because some users want only the text larger (without bigger buttons), some want everything scaled, and some need text that is both larger and heavier. Each setting targets a slightly different problem, and turning on all three together is what most seniors actually need.

Setting 1: Text Size

Open Settings → Display & Brightness → Text Size. Drag the slider toward the right. Test against the live preview at the top of the screen — when the sample text feels effortless to read at arm's length, stop. There is no penalty for going large.

This is the setting that affects Messages, Mail, Notes, Calendar, and most apps that respect Apple's "Dynamic Type" system.

Setting 2: Bold Text

In the same screen, scroll up one row and turn on Bold Text. The phone may briefly flash. Bold Text thickens every letter on the system and most apps. For anyone with macular degeneration, cataracts, or simply tired eyes, bold text is more readable than bigger text — and the two combine.

Setting 3: Display Zoom

Still in Display & Brightness, scroll down to Display Zoom. Tap it, then choose Larger Text (on most models the choices are "Default" and "Larger Text"). The phone will restart. After the restart, icons, the keyboard, and Control Center buttons will all be visibly larger. This is the setting that finally makes the home screen feel comfortable, and it is the one most users miss.

Per-app text size (the secret one)

You can set text size differently for each app. Open Settings → Accessibility → Per-App Settings, tap Add App, choose Safari, then tap into the new Safari row and pick a larger Text Size. Now Safari can be larger than Mail without you having to compromise.

If you only do this for one app, do it for Safari — websites famously ignore iPhone's main text-size setting, and per-app settings are the only reliable fix.

Why your change didn't seem to work

The two most common reasons a text-size change appears not to work:

• The app does not support Dynamic Type. Many older apps and most games ignore iPhone's text-size setting. Use per-app settings (above) or contact the app developer.
• You changed Text Size but not Display Zoom. Text Size enlarges text inside apps. Display Zoom enlarges the whole interface. For "everything looks bigger," you need both.

For more accessibility settings worth turning on, see our full iPhone setup walkthrough.