Introduction

Changing the font of tab bar item titles in Swift means customizing UITabBarItem title text attributes. The exact API depends on the iOS styling path you are using, but the core idea is the same: set the desired font for the normal and selected states and keep the visual style consistent across the tab bar.

Global Customization with UITabBarItem.appearance()

The classic solution is to use the appearance proxy for all tab bar items in the app.

1import UIKit
2
3let normalAttributes: [NSAttributedString.Key: Any] = [
4    .font: UIFont.systemFont(ofSize: 11, weight: .regular)
5]
6
7let selectedAttributes: [NSAttributedString.Key: Any] = [
8    .font: UIFont.systemFont(ofSize: 11, weight: .semibold)
9]
10
11UITabBarItem.appearance().setTitleTextAttributes(normalAttributes, for: .normal)
12UITabBarItem.appearance().setTitleTextAttributes(selectedAttributes, for: .selected)

This is simple and works well when the whole app uses one tab-bar style.

Using a Custom Font

If the design requires a custom font, create it with a fallback so the app stays stable if the font name is wrong or the resource is missing.

1let customFont = UIFont(name: "AvenirNext-DemiBold", size: 11) ??
2    UIFont.systemFont(ofSize: 11, weight: .semibold)
3
4UITabBarItem.appearance().setTitleTextAttributes(
5    [.font: customFont],
6    for: .selected
7)

The fallback matters because UIFont(name:size:) returns nil if the font is unavailable.

iOS 13 and Later: UITabBarAppearance

On newer iOS versions, UITabBarAppearance gives more control over tab-bar styling and is often the better modern path.

1import UIKit
2
3let appearance = UITabBarAppearance()
4appearance.configureWithDefaultBackground()
5
6appearance.stackedLayoutAppearance.normal.titleTextAttributes = [
7    .font: UIFont.systemFont(ofSize: 11, weight: .regular)
8]
9
10appearance.stackedLayoutAppearance.selected.titleTextAttributes = [
11    .font: UIFont.systemFont(ofSize: 11, weight: .semibold)
12]
13
14UITabBar.appearance().standardAppearance = appearance
15
16if #available(iOS 15.0, *) {
17    UITabBar.appearance().scrollEdgeAppearance = appearance
18}

This approach fits better when you are already using the modern appearance APIs for color, background, and icon styling.

Apply the Style Early

Set tab-bar appearance during app startup so every controller uses the same configuration. In UIKit apps, that usually means AppDelegate, SceneDelegate, or the setup code that builds the root tab bar controller. Applying appearance rules after some screens are already visible can produce inconsistent results.

1final class AppDelegate: UIResponder, UIApplicationDelegate {
2    func application(
3        _ application: UIApplication,
4        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
5    ) -> Bool {
6        let font = UIFont.systemFont(ofSize: 11, weight: .medium)
7        UITabBarItem.appearance().setTitleTextAttributes([.font: font], for: .normal)
8        return true
9    }
10}

Per-Item Customization

If one tab item needs special styling, set the text attributes directly on that item instead of using the global appearance proxy.

1viewController.tabBarItem.setTitleTextAttributes(
2    [.font: UIFont.systemFont(ofSize: 12, weight: .bold)],
3    for: .normal
4)

This is less common, but it is useful when a specific tab needs a different visual treatment.

Keep Font, Color, and Layout Together

Font changes affect perceived spacing, balance, and readability. When you change the title font, also review:

• selected and unselected text colors
• icon alignment
• text size on smaller devices
• accessibility and Dynamic Type expectations

A heavier or larger font can make a tab bar feel crowded even when the code is technically correct.

Common Pitfalls

Setting the font only for .normal and forgetting .selected can make the tab bar look inconsistent when the user changes tabs.

Using a custom font name that is not actually bundled in the app causes the customization to fail silently unless you provide a fallback.

Mixing older appearance-proxy code with newer UITabBarAppearance settings without understanding which one wins can create confusing results.

Changing the font without checking the resulting spacing can make tab titles feel cramped or misaligned.

Applying app-wide appearance changes too late in the app lifecycle can make some controllers render with old styles and others with new ones.

Summary

• Tab bar fonts are controlled through UITabBarItem title text attributes.
• Use UITabBarItem.appearance() for simple app-wide styling.
• Use UITabBarAppearance on newer iOS versions for more modern, structured customization.
• Provide a fallback when using custom fonts.
• Check selected and normal states together so the tab bar stays visually consistent.