12 UX Laws Every Designer Should Know

Good design isn't just intuition. Much of what makes an interface feel easy is grounded in how people perceive, think, and act. Over decades, researchers and practitioners have captured these patterns as principles often called UX laws.

They're not rigid rules, but they're reliable guides for making better decisions and explaining those decisions to others. Here are twelve worth knowing.

1. Jakob's Law#

Users spend most of their time on other sites and apps, so they expect yours to work the same way.

People bring expectations from every other product they use. When you follow established conventions — a logo linking home, a cart icon in the top corner, a search field that looks like a search field — users can rely on what they already know.

Apply it: Use familiar patterns for common tasks. Innovate where it adds real value, not on things users already understand.

2. Fitts's Law#

The time to reach a target depends on its size and distance.

Large targets that are close to the user's current position are faster and easier to hit. Small, distant targets are slow and error-prone.

Apply it: Make important buttons large enough, place frequent actions within easy reach — especially on mobile, where thumbs have limited range — and give touch targets enough space to avoid mis-taps.

3. Hick's Law#

The time it takes to make a decision increases with the number and complexity of choices.

More options mean more thinking. Long menus, crowded dashboards, and pages with many competing calls to action slow users down.

Apply it: Reduce choices where possible, highlight recommended options, break complex decisions into steps, and use progressive disclosure to reveal advanced options only when needed.

4. Miller's Law#

People can hold only a limited number of items in working memory at once.

Often summarized as "seven, plus or minus two," the real point is that working memory is limited. Presenting too much information at once overwhelms people.

Apply it: Chunk information into meaningful groups. Phone numbers are split into segments for a reason. Use clear grouping, headings, and spacing to make content digestible. Don't use the number seven as a hard limit on menu items — it's about chunking, not counting.

5. Tesler's Law#

Every system has a certain amount of complexity that cannot be removed — only moved.

The question is who deals with it: the user or the system. Good design absorbs complexity so users don't have to.

Apply it: Automate what you can, use smart defaults, and handle technical details behind the scenes. But don't oversimplify to the point of removing control users genuinely need.

6. The Law of Proximity#

Objects that are near each other are perceived as related.

This Gestalt principle is one of the most powerful layout tools. Spacing alone can communicate structure without any lines or boxes.

Apply it: Place related items close together and separate unrelated groups with more space. Keep labels close to their inputs and away from neighboring fields.

7. The Law of Similarity#

Elements that look similar are perceived as related or as having the same function.

Consistent styling helps users understand what things do. If all links look the same, users learn to recognize them instantly.

Apply it: Style elements with the same function consistently, and make elements with different functions look different. Don't make non-clickable text look like a link.

8. The Von Restorff Effect#

When multiple similar objects are present, the one that differs is most likely to be remembered.

Also called the isolation effect, this is why a single highlighted plan on a pricing page draws attention.

Apply it: Make key actions or information visually distinct — but use it sparingly. If everything is highlighted, nothing stands out. And don't rely on color alone for the distinction.

9. The Serial Position Effect#

People best remember the first and last items in a series.

Items in the middle of a list are more easily forgotten.

Apply it: Place the most important items at the beginning and end of navigation menus, lists, and content. Put less critical items in the middle.

10. The Peak-End Rule#

People judge an experience largely by how they felt at its most intense point and at its end.

Users don't average every moment of an experience. They remember the peaks — good or bad — and the ending.

Apply it: Identify the moments that matter most, like completing a purchase or finishing onboarding, and make them delightful. Pay special attention to endings, and minimize painful peaks like confusing errors or lost data.

11. The Doherty Threshold#

Productivity soars when a computer and its users interact at a pace that ensures neither has to wait on the other.

Research suggested that responses within roughly 400 milliseconds keep users engaged and in flow.

Apply it: Optimize performance, give immediate feedback for every interaction, use skeleton screens and optimistic updates, and show progress for longer operations so waits feel shorter.

12. The Aesthetic-Usability Effect#

Users often perceive aesthetically pleasing design as more usable.

Attractive interfaces create a positive first impression and make users more tolerant of minor issues.

Apply it: Invest in visual quality — but don't let it hide real usability problems. A beautiful interface can mask issues in usability testing, so watch what users do, not just what they say.

Laws are guides, not formulas#

UX laws are most useful as a shared vocabulary and a starting point. They help you predict how users might behave and explain design decisions to stakeholders. But they don't replace research. Real users in real contexts will always surprise you.

Use these principles to make better first drafts, then test with real people to find out what actually works.