WWDC 2026: Principles of great design (Session 250)

A practical framework for designing Apple-platform experiences with purpose, agency, responsibility, familiarity, flexibility, simplicity, craft, and delight.

Watch on Apple Developer

TL;DR

Design is framed as intentional decision-making: every feature asks for a person's time, attention, and trust, so omission is as important as addition.
Great Apple-platform experiences give people agency through choice, direct exploration, undo, and careful confirmation for destructive actions.
Responsible design minimizes data requests, asks at the right moment with context, and anticipates misuse or harm, especially when adding AI capabilities.
Familiarity, flexibility, simplicity, craft, and delight help teams choose conventions, adapt across contexts and abilities, reduce friction, polish details, and build emotional connection.

The session defines design as making something with intention, not just how something looks or behaves. A product should focus on what matters most to people and deliver something they will truly value.

Every feature has a cost: it asks for time, attention, and trust. Before sketching or writing code, evaluate whether a feature has real purpose, and be willing to decide what not to include.

Use purpose as an early filter for product and feature decisions.
Prefer experiences that serve people, respect their lives, adapt to their contexts, and are clear and considered.
There is no formula for combining the principles; design judgment is required when principles appear to conflict.

Agency and forgiveness

Agency means putting people in control. Interfaces should avoid forcing people through predetermined paths when exploration would serve them better, and should let people proceed at their own pace.

Because agency means people can make mistakes, good design includes forgiveness. Undo, recovery paths, and selective confirmations help people feel safe enough to explore.

Offer meaningful choices instead of blocking the person's goal.
Make it easy to undo actions such as sending, changing, or deleting.
Confirm destructive actions when the cost of a mistake is high.
Use interruptions sparingly; they are most appropriate when preventing a major mistake.

Responsibility, privacy, and safety

Responsibility on Apple platforms starts with treating privacy as a human right. A design should not request personal information or permissions at launch without context or an immediate need.

Responsible teams also consider who could be harmed by a feature and how it could be misused. For AI-powered features, this includes anticipating unexpected or inaccurate model output and adding safeguards where appropriate.

Ask only for data that is necessary.
Request permissions at the moment they are needed, with clear context for why.
Evaluate possible misuse: who could be harmed, how harm could happen, and how to prevent it.
For risky AI features, consider previews, confirmations, disclaimers, or removing the feature if the safety risk outweighs its value.

Familiarity and flexibility

Familiarity lets people apply existing knowledge from the real world and from other interfaces. Metaphors, platform conventions, consistent behavior, and consistent placement help people predict what will happen.

Flexibility recognizes that people use products in different contexts, on different devices, with different abilities and preferences. A design should adapt to the strengths of each platform and, when one solution cannot fit everyone, allow personalization.

Use familiar metaphors for common actions, such as trash for delete, and avoid assigning familiar icons surprising meanings.
Keep behavior consistent: things that look the same should work the same.
Design for platform context: quick touch interactions on iPhone, deeper workflows and precise pointer control on Mac, and hands-free or wearable contexts when relevant.
Consider audience differences such as age, language, experience level, and reliance on accessibility features.
Support personalization when appropriate, such as rearranging or hiding controls to fit individual workflows.

Simplicity and craft

Simplicity is not the same as minimalism. A minimal-looking interface can still be hard to use if functionality is hidden or workflows require too much effort. Simplicity means reducing friction so people can find what they need and complete tasks naturally.

Craft is the attention to detail that makes software feel trustworthy. Performance, alignment, layout behavior, typography, color, graphics, iconography, animation, reliability, and security all contribute to whether an experience feels solid or fragile.

Use plain language, avoid jargon, remove redundancy, and reduce unnecessary steps.
Build clear hierarchy with order, spacing, and contrast so the most important element is obvious.
Make affordances understandable: people should know what they can interact with and how.
Let every element earn its place, but add context when it makes decisions easier, such as progress and remaining time on media controls.
Iterate and maintain the design over time as platforms, hardware, and user needs evolve.

Delight as the result of care

Delight is described as a satisfying, enriching emotional connection, not as decorative effects added at the end. It comes from identifying the emotion the experience should create-such as relaxation, confidence, or excitement-and reinforcing it through the whole design.

When a product combines intention, agency, safety, familiar patterns, flexibility, simplicity, and craft, delight becomes the natural result. The session points developers and designers to the Human Interface Guidelines design principles page for deeper guidance.

Do not rely on superficial flourishes to create delight.
Design the emotional outcome intentionally.
Use the full set of principles together to create experiences people trust and enjoy.

Resources

Human Interface Guidelines: Design principles

Principles of great design