Introduction

Changing the font of a UIBarButtonItem is usually done through text attributes, either per item or globally through appearance proxies. Unlike normal labels, bar button items are rendered by navigation/toolbar systems and can apply style differently by state and context.

For predictable results, set title text attributes for each control state (normal, highlighted, disabled) and test in both standard and large-title navigation configurations.

Core Sections

1. Set font on a single bar button item

1import UIKit
2
3let item = UIBarButtonItem(title: "Save", style: .plain, target: self, action: #selector(saveTapped))
4item.setTitleTextAttributes([
5    .font: UIFont.systemFont(ofSize: 17, weight: .semibold),
6    .foregroundColor: UIColor.systemBlue
7], for: .normal)

Also define disabled state if needed:

1item.setTitleTextAttributes([
2    .font: UIFont.systemFont(ofSize: 17, weight: .semibold),
3    .foregroundColor: UIColor.systemGray
4], for: .disabled)

2. Apply app-wide style with appearance

1let attrs: [NSAttributedString.Key: Any] = [
2    .font: UIFont(name: "AvenirNext-DemiBold", size: 16)!,
3    .foregroundColor: UIColor.label
4]
5UIBarButtonItem.appearance().setTitleTextAttributes(attrs, for: .normal)

Use cautiously if different screens need distinct styles.

3. Prefer UINavigationBarAppearance for modern nav bars

1let navAppearance = UINavigationBarAppearance()
2navAppearance.configureWithOpaqueBackground()
3navAppearance.buttonAppearance.normal.titleTextAttributes = [
4    .font: UIFont.systemFont(ofSize: 16, weight: .medium)
5]
6UINavigationBar.appearance().standardAppearance = navAppearance
7UINavigationBar.appearance().scrollEdgeAppearance = navAppearance

This is often more reliable on newer iOS versions.

4. Use custom view for advanced typography

If you need precise kerning, multi-line behavior, or custom animation, place a UIButton as customView in UIBarButtonItem.

5. Test dynamic type and accessibility

Custom fonts should still scale if your app supports Dynamic Type. Consider UIFontMetrics for accessible scaling.

Common Pitfalls

• Setting attributes only for .normal and forgetting disabled/highlighted states.
• Using global appearance styling that unintentionally affects unrelated screens.
• Relying on legacy nav bar APIs while using modern UINavigationBarAppearance.
• Expecting custom font behavior identical across iOS versions without testing.
• Ignoring Dynamic Type and shipping inaccessible bar button text.

Summary

To change UIBarButtonItem font, use setTitleTextAttributes for item-specific styling or UINavigationBarAppearance/appearance proxies for broader theming. Define per-state attributes and validate behavior across navigation modes and accessibility settings. With consistent configuration, bar button typography stays predictable and visually coherent.

A practical way to make this guidance durable is to convert it into a small runbook that includes prerequisites, expected environment versions, and a short verification sequence. Even strong teams lose time when troubleshooting steps live only in memory or chat history. A runbook should explicitly answer three questions: what to check first, what output confirms healthy behavior, and what output indicates a known failure mode. This level of clarity helps both experienced maintainers and newer contributors, and it reduces repeated investigation during incidents.

It is also valuable to create a tiny reproducible fixture for this topic. The fixture can be a minimal script, test case, sample request, or small dataset that demonstrates the correct behavior in isolation. When regressions appear after dependency upgrades, infrastructure changes, or framework migrations, that fixture becomes the fastest way to isolate whether the issue is environmental or logic-related. Keeping a focused fixture in source control gives you a stable benchmark across branches and release cycles.

For long-term reliability, pair documentation with one automated guardrail in CI. The guardrail should be narrow and fast: an import check, schema validation, endpoint contract test, deterministic unit test, or lightweight performance threshold. Avoid broad flaky checks that hide real signals. The goal is early, actionable feedback before code reaches production. If the same category of issue appears repeatedly, promote the manual troubleshooting step into automation so the system catches it first. Over time, this shifts effort from reactive debugging to preventive quality control and keeps the knowledge article relevant in real engineering workflows.

As a final hardening step, periodically rerun the sample code in a clean environment image and record results in version control. This catches ecosystem drift early and keeps implementation guidance aligned with real runtime behavior.