Jakob's Law
People spend most of their time on other products, so they expect yours to work the way those do.
Definition
Jakob Nielsen's observation that users build expectations from the cumulative experience of every other interface they use. Meeting those expectations is nearly free; violating them charges the user a learning cost that your product has to be worth.
Craft convention. True because the industry converged on it. Breaking it costs familiarity, not correctness.
On this plate
Reach for this when
- Designing navigation, forms, checkout or any low-frequency task.
- Entering an established category where competitors have trained the user already.
- Deciding whether a novel interaction is worth its teaching cost.
- A proposal replaces a familiar control with a better one, and nobody has priced the relearning.
Common mistakes
- Using the law to justify copying a competitor's bad pattern.
- Assuming conventions are global when they are category specific.
- Testing convention breaks only with expert internal users.
Why it holds anyway
Conventions are a shared cache. A logo at the top left that returns home, a cart icon at the top right, an underlined blue link, a hamburger on mobile: none of these are intrinsically correct, but they are known. Reusing them means the user spends their attention on your content instead of on your chrome.
The cost of breaking a convention is not the moment of confusion. It is the ongoing tax on every subsequent interaction until the new model is learned, multiplied by the users who leave before learning it.
Conventions worth keeping unless you have a strong reason
- Logo top left, linking to the home page.
- Primary navigation across the top on desktop, bottom on mobile apps.
- Search represented by a magnifier, positioned top right or in a prominent bar.
- Cart or account in the top right corner.
- Form labels above inputs, errors below the field they belong to.
- Primary action on the right in a horizontal button pair on the web, following platform order in native dialogs.
- Underline or clear color difference for inline links.
When to break it
Break a convention when the convention is genuinely bad for your task and you can afford to teach the new model. Professional tools do this constantly: Figma's canvas, a code editor's command palette and a DAW's timeline all violate general web conventions and are correct to.
The test is whether the user's task is frequent enough to amortise learning. A convention break in a tool someone uses eight hours a day is an investment. The same break on a checkout page someone visits twice a year is a leak.
In practice
Do
- Be conventional in navigation, forms and checkout. Be distinctive in content, voice and the parts that are genuinely your product.
- Test convention breaks with people who have never seen your product, not with your team.
- Adopt platform conventions for platform surfaces: date pickers, share sheets, back behaviour.
Do not
- Rename standard actions for brand voice. 'Add to bag' is fine. 'Acquire' is not.
- Invent a new scroll behaviour on a content page.
- Confuse visual distinctiveness with structural novelty. You can look unlike everyone else while behaving like everyone else.
What breaking a convention costs
Every departure is a bet that your version is better by more than the learning cost. Some bets are cheap and some are not.
| Convention | Cost of breaking it |
|---|---|
| Logo returns to home | Low visible cost, constant low-level friction, and nobody reports it |
| Underlined blue text is a link | Missed navigation, and a real accessibility failure when colour is the only cue |
| Cart at the top right | Measurable on an ecommerce funnel within days |
| Back gesture and browser back | Lost work and abandoned sessions, the most expensive break of the set |
| Scroll position and momentum | Motion sickness for some readers, and a sense that the page is broken for the rest |
In practice
- i.
Ecommerce cart placement
RetailMoving the cart out of the top right corner reliably produces support tickets and abandoned sessions, even when the new placement is objectively more visible. The expectation is stronger than the salience.
- ii.
Command palettes
Developer toolsThe Cmd+K palette started as a convention break in code editors, spread across professional tools, and is now itself a convention for that class of product. Conventions are local to a category, not global.
- iii.
Novelty in the wrong place
Where to spend originalityA distinctive product can be built out of conventional navigation, conventional forms and one thing nobody else does. Spending the novelty budget on the menu leaves nothing for the part people came for.
Commonly confused with
Close neighbours that get substituted for each other. The difference is stated first, then the condition that picks one over the other.
Consistency and Standards
HeuristicThe same word, control and behaviour meaning the same thing throughout one product.
Key difference
Consistency is internal: the same thing behaves the same way across your product. Jakob's Law is external: your product should behave the way the rest of the web already does. A product can be perfectly consistent with itself and still surprise everyone who arrives.
Use Jakob's Law when
- You are considering a novel take on a familiar control.
- The question is whether to follow a platform or web convention.
- The cost of the difference lands on first-time users.
Use Consistency and Standards when
- Two screens solve the same problem differently.
- The vocabulary drifts between areas or teams.
- The fix is a shared component, token or term.
Local chart
LAW·003 · Region I · Grid B2
This entry and the entries it is stated to connect with. Each line is labelled with what the connection means.
Sources
Where a source establishes something narrower than the popular reading of it, the note says so.
- [1]
Jakob's Law of Internet User Experience
J. Nielsen, Nielsen Norman Group, 2000
Originally stated in the context of web design conventions.
- [2]
Criteria for optimal web design (designing for usability)
M. Bernard, Software Usability Research Laboratory, 2003
Empirical work on where users expect common web elements to be located.
Continue from here
Each link says what the connection is, so you can tell a principle from an alternative from a thing people mix this up with.
Applies when you are designing
Why this works
The reasoning this entry rests on.
- Status Quo BiasBIAS·005 · Cognitive bias
- Mental ModelsMOD·001 · Mental model
Convention is valuable because it matches a model people already hold.
- Mere Exposure EffectPSY·009 · Psychology
Applied through
Where this shows up as a concrete interface decision.
- Design Brief to Wireframe DirectionAI·008 · AI workflow
- Design System AdoptionSYS·005 · Design system
- NavigationPAT·001 · Pattern
- Competitive AnalysisRES·019 · Research method
Check your work
Review passes that test whether this was done properly.
- Ecommerce ChecklistCHK·006 · Checklist
- Web UX ChecklistCHK·011 · Checklist
Short definition
The one-paragraph version, for when that is all you need.
- Design PatternTERM·038 · Term
- Mental ModelTERM·009 · Term
Related concept
Connected closely enough to change how you apply this.
- Match Between System and the Real WorldHEUR·002 · Heuristic
- Recognition Over RecallHEUR·006 · Heuristic