Learn UX by testing it on yourself.
30 short experiments. Each one shows you a real law of how people think. Free. No login.
Built by Asim Sharif
The laws
of UX, tested on
you.
30 laws. Each one has a short test you take right here. Take the test, see your own result, then read the law. No experience needed.
Hick's Law
More choices, slower decisions. Tap a color from 3 options, then from 12, and watch your own hesitation get measured.
Doherty Threshold
Under 400ms an interface feels alive. Run the same search on two systems, only the delay differs.
Zeigarnik Effect
Unfinished tasks stick in memory. Three project cards flash, the interrupted one is the one you'll remember.
Selective Attention
Count the blue words. Just the blue words. (Did you notice the gorilla?)
30 laws, playable.
Each card opens into a full entry: the definition, a live experiment that runs on you, three field sightings, and a design takeaway. Your progress is saved on this device, reset any experiment, or the whole lab, whenever you like.
Hick's Law
The more choices people see, the longer they take to decide.
Tap a named color, first from 3 options, then from 12. We time both.
- Google's homepage: one box, one job, everything else amputated.
- McDonald's kiosks show categories first, never all 100 items at once.
- Netflix's homepage groups thousands of titles into a handful of curated rows, like Top 10 and Continue Watching, so you never face the full catalog at once.
Fitts's Law
Big, close targets are quick to tap. Small, far ones are slow.
Tap 6 circles as fast as you can. They shrink as you go.
- Apple's rule: nothing tappable smaller than 44pt on iOS.
- "Place order" is always the biggest thing on screen; "cancel subscription" is a tiny gray link.
- The Spotify's play/pause button stays large and fixed at the bottom of the screen across every view, so it's always an easy, forgiving tap regardless of what you're browsing.
Miller's Law
People can hold only about 7 things in their head at once.
Digits flash, then vanish. Type them back. Rounds get longer, until you break.
- Phone numbers ship pre-chunked: 0300-1234567, never 03001234567.
- OTPs are 6 digits, not 10, past seven, humans drop the packet.
- Amazon's checkout breaks address, payment, and review into separate short steps instead of one long form that would overflow working memory.
Serial Position Effect
People remember the first and last items in a list best.
9 words flash one by one. Then type every word you remember.
Positions you recalled
- Nav bars put "Home" first and "Sign up" last, never in the middle.
- Pricing pages place the plan they want you to buy at the edge of the row.
- Duolingo's lesson-complete screen ends on the streak count, the last thing you see and the thing you remember, because the end of a list is what sticks.
Von Restorff Effect
The item that looks different is the one people remember.
9 words appear for 3 seconds. Then type the first word that comes back.
- One glowing "Most popular" plan among gray siblings.
- A single colored CTA on an otherwise monochrome page.
- On Airbnb's search results, a single "Guest favorite" badge stands out among otherwise similar listing cards, and it's the one detail most people recall afterward.
Jakob's Law
People expect your site to work like the sites they already use.
Same task, two forms: tick the box, submit. One follows convention. One doesn't. Both timed.
- Logo top-left takes you home. Everywhere. You've never read documentation for this.
- The cart lives top-right and search is a magnifying glass, imported expectations, not taught ones.
- Airbnb keeps its search bar, filters, and map in the same familiar places users expect from years of travel-booking sites, so switching from a competitor feels immediate, not like learning new software.
Doherty Threshold
Respond in under 400ms and people stay engaged. Slower, and their mind drifts.
Run the same search on two systems. Only the delay differs.
- Spotify's heart and playlist-add icons fill the instant you tap them, before any server confirmation returns, so the interface never feels like it's making you wait on your own action.
- YouTube and LinkedIn paint skeleton screens so the wait feels like progress.
- Google autocomplete answers in under 100ms, the interface keeps pace with your thoughts.
Goal-Gradient Effect
The closer people feel to a goal, the harder they push to finish it.
Two coffee loyalty cards. Pick the one you'd rather complete.
- Netflix's "Continue Watching" row shows a partially filled progress bar under each show, and that visible incompleteness is part of what pulls you back to finish it.
- "Add Rs. 200 more for free delivery" turns a fee into a finish line.
- Spotify Wrapped turns a year of listening into a countdown of milestones users track through December, each one building anticipation for the next reveal.
Aesthetic-Usability Effect
Designs that look good feel easier to use, even when they are not.
Two calculator apps. Tap the one that's easier to use.
- Apple product pages sell perceived quality before a single spec appears.
- A polished prototype hides real usability problems in user testing, testers forgive beauty.
- Airbnb's 2014 redesign: same listings, new polish, and trust metrics jumped.
Tesler's Law
Every product has complexity. Someone has to handle it: the user or the system.
- Address autocomplete: you type 5 characters, the system fills 5 fields.
- "Sign in with Google" moves the entire password problem to someone else's servers.
- Careem and Uber read your pickup point from GPS, complexity absorbed, not deleted.
Postel's Law
Accept messy input from people. Give back clean, predictable output.
Type a phone number however you like, spaces, dashes, brackets, into both fields.
- Good card fields accept "4242 4242 4242 4242" with spaces and quietly strip them.
- Google doesn't scold your typo, it answers what you meant and whispers "did you mean".
- A forgiving phone field takes +92, 0092, dashes, brackets, and stores clean digits either way.
Parkinson's Law
A task stretches to fill however much time you give it.
Type the word DESIGN twice, once with a lazy 20s deadline, once with a scary 5s one. Same task. We time you.
- Booking.com's countdown timers compress your decision into their deadline.
- "Only 2 left in stock" manufactures the tight-deadline focus you just felt.
- Gmail's "Undo Send" gives you a fixed 30-second window; the tight deadline forces a fast decision instead of letting second-guessing expand to fill an open-ended pause.
Peak-End Rule
People judge an experience by its strongest moment and its ending, not the average.
Two support chats, same length. Which experience was better?
- Mailchimp's high-five when you hit send, the peak, engineered.
- Airbnb ends a stay with a simple, low-friction review prompt rather than a lengthy survey, so the last impression of the whole booking stays light.
- IKEA's exit ice cream: hours of maze, but you leave holding a happy ending that cost them almost nothing.
Zeigarnik Effect
People remember unfinished tasks better than finished ones.
3 project cards appear for 3 seconds. Then tell us which one you remember.
- Netflix's "Continue Watching" row is built entirely on this effect: an unfinished episode nags at memory in a way a finished series never does.
- Cart-abandonment emails work because the unfinished purchase is still nagging you.
- That "73% complete" badge on your profile, designed to itch until you scratch it.
Law of Proximity
Things placed close together look like they belong together.
How many groups do you see?
- A form label sits closest to its own field, move it and errors spike.
- Price hugs the product photo; float it away and shoppers mismatch items.
- Instagram places each caption directly beneath its photo and the username right above it, so proximity alone tells you which text belongs to which post.
Law of Similarity
Things that look alike seem related, even when they are far apart.
What do you see, rows or columns?
- Every link on a page is the same blue, sameness silently means "I behave the same".
- Destructive actions are always red; make one green and watch users delete things.
- Spotify styles every playable item, songs, albums, playlists, with the same green play affordance, so similarity tells you they all behave the same way.
Law of Common Region
Items inside the same border are seen as one group.
Dot 3 and dot 4 are closest to each other. Do they feel like a pair?
- Cards. Every dashboard, feed, and app store is boxes declaring what belongs together.
- Pricing tables draw a border around each plan so features never leak between columns.
- WhatsApp encloses each message in its own bubble, and that shared boundary is what groups a multi-line message as one unit rather than separate lines.
Occam's Razor
When two designs work equally well, the simpler one wins.
You need a flight, Lahore → Dubai, next Friday. Which search would you actually use?
- Google Flights defaults to three fields; the other fifty hide behind one click.
- WhatsApp opens straight into your chats, the one thing 99% of opens are for.
- Stripe's checkout became the benchmark by deleting every field it possibly could.
Law of Prägnanz
People see the simplest possible shape, even in a complex image.
What did you just see?
- Mastercard is technically two overlapping circles and a lens, you see one simple mark.
- Line icons survive at 16px because they're already the simplest possible interpretation.
- Google Maps redraws tangled real-world roads as clean simplified lines, because the eye prefers the simplest shape that still communicates the route.
Uniform Connectedness
A line connecting two things groups them more strongly than color or spacing.
Which dots pair together, the connected ones, or the same-colored ones?
- Checkout steppers: dots joined by a line read as one journey, not four labels.
- Org charts and flow diagrams: the connector line *is* the information.
- Figma's prototype connections draw a literal line between two frames, and that connector is what turns two separate screens into one understood flow.
Choice Overload
Show too many options and people pick nothing at all.
Buy a jam, first from a shelf of 4, then from a shelf of 16. We time you, then ask how you felt.
- The original jam stand: 24 flavors drew a crowd, 6 flavors sold ten times more.
- Netflix pushes curated rows because the full catalog is where decisions go to die.
- Smart restaurant menus mark "chef's picks", a shortlist inside the longlist.
Chunking
Break information into small groups and it becomes easy to remember.
Memorize two 10-digit numbers, one raw, one chunked. Same length, same time on screen.
- Card numbers render in groups of four: 4242 4242 4242 4242.
- IBANs get spaced into blocks because 24 raw characters are unreadable.
- WhatsApp displays phone numbers in spaced country-code chunks rather than one long string, because grouped digits are far easier to read and verify.
Cognitive Load
Every extra thing on screen uses up a bit of the user's mental energy.
Find and tap SETTINGS, first in a clean menu, then in a cluttered one. We time both.
- Nearly every "clean redesign" case study that lifted conversion, same features, lower tax.
- Google's homepage outlived busy 2000s portals that buried search under widgets and news.
- Airline sites tuck 30 filters behind one "Filters" button so the fare list can breathe.
Selective Attention
When people focus on one task, they stop seeing everything else.
A grid of words appears for 4 seconds. Your job: count the BLUE words. Nothing else matters.
- Banner blindness: users have learned to unsee anything shaped like an ad.
- A user hunting the "Continue" button will walk straight past your inline error message.
- YouTube's subtle "Skip Ads" button is easy to miss for a first-time viewer focused on their video, exactly because focused attention makes everything outside the task fade.
Paradox of the Active User
People start using products right away. They do not read instructions first.
A brand-new gadget arrives at your door. Honestly, what do you do first?
- Onboarding is skippable everywhere, because everyone skips it.
- Empty states now teach ("Create your first project"), the manual, smuggled into the flow.
- Notion teaches through empty-state prompts like "Type '/' for commands" right where you'll act, because users dive in and never read a manual first.
Pareto Principle
Around 80% of the results come from 20% of the features.
Microsoft Word has ~1,000+ commands. What share of them does a typical user's work actually rely on?
- The iPhone camera: one shutter button carries 80% of use; pro controls hide a swipe away.
- Microsoft's own telemetry drove the ribbon: a handful of commands dominated everything.
- Your TV remote has 40+ buttons. Count how many you've pressed this month.
Law of Continuity
The eye follows smooth paths. Lines that flow together are seen as one.
How many lines do you see?
- Line charts: you read each series as one flowing line, even where they cross.
- Steppers and timelines pull the eye along a single path from start to finish.
- Airbnb's search results flow down one continuous vertical column, so the eye keeps scanning naturally from one listing to the next without deciding where to look.
Law of Closure
People see complete shapes, even when parts are missing.
What do you see?
- Loading spinners: an arc with a gap still reads as a circle in motion.
- Logos built from incomplete shapes that your brain finishes on its own.
- Netflix crops the last thumbnail in each row at the screen edge; your brain completes the hidden card, and that incompleteness is what signals "swipe for more."
Figure-Ground
People split every scene into a subject and a background.
What did you see first?
- Modal overlays: dimming the page pushes it to ground so the dialog becomes the figure.
- Negative-space logos hide a second image in the background, like an arrow inside a wordmark.
- Instagram Stories adds a subtle gradient behind the top icons so they stay the clear figure against whatever photo or video sits behind them.
Law of Symmetry
Mirrored elements are seen as belonging together, as pairs.
What do you see?
- Split-screen layouts: two mirrored halves read as one balanced composition.
- Comparison tables: symmetric columns tell you the plans are equals.
- iMessage mirrors your bubbles on the right against theirs on the left in balanced symmetry, so the whole thread reads as one calm, ordered conversation.
The library.
30 laws cover the big moments. This covers the rest: biases, nudges, dark patterns to avoid, usability rules, accessibility, and how AI changes interfaces. Ten shelves. One search bar. Every entry sourced.
Why so much here? Because most design decisions are small ones. A law explains a pattern. A library entry shows you where that pattern actually shows up, like the bias a checkout screen uses, or the exact rule a form breaks. Each entry takes under a minute to read, so you can look something up mid-project instead of reading a whole book first.
The roadmap.
24 weeks. Learn UX design, step by step, two weeks at a time.
About LearnUX Lab.
I used to open 20+ tabs to study UX laws. So I built the single page I wished existed.
Studying UX meant jumping between Wikipedia, NNGroup, research papers, and random Medium articles, losing context every time. Laws were scattered, sources were unverified, and half the explainers got the science wrong. I wanted one trusted place where every law is sourced, every reference is linked, and nothing is made up.
Hi, I'm Asim Sharif
I'm a UX designer with 3.5+ years of experience shipping real products. I built LearnUX Lab not as a course or a business, but as my own study companion. Every law here is checked against original research, and every reference links back to the people who actually discovered it.
What makes this different
Unlike generic UX blogs that paraphrase without attribution:
✓ Every law is checked against original research
✓ Every source links back to the original author or paper
✓ No paywall, free to learn and free to share
✓ Built by a practicing designer, not a content farm
✓ Global search, find any law in seconds
What's inside
· 30 UX laws, each with a live experiment that runs on you
· Nielsen's 10 usability heuristics, with interactive examples
· 120+ entries across biases, nudges, dark patterns, Gestalt, WCAG, and AI × UX
· Real-world examples, quick checks, and design takeaways
· Free tools and research resources
Know someone studying this too?
If a law here made something click for you, that's exactly why this exists. Sharing it costs nothing. Send a friend the whole lab, or just the one law they need.
Help make it better
This is a living project and I would genuinely like your help. Found a law with a shaky source? Know a psychology finding that deserves a spot here? Spotted a typo, a broken link, or an experiment that behaves oddly on your device? Tell me.
Email me directly at imaasimsharif@gmail.com, whether it is one line or a whole write-up. Every message gets read, and if your suggestion makes it in, you will be credited for it.
Say hello
Questions, feedback, or just want to talk UX? imaasimsharif@gmail.com or find me on LinkedIn.
A note on honesty: single-person trials are noisy. If you beat a law once, run it again. These effects are statistical tendencies proven across thousands of participants, not iron guarantees about any one attempt. That is exactly how you should treat them in design work too.
Ask LearnUX AI
Your UX design tutor. Ask about laws, heuristics, accessibility, AI in design, or design engineering.