3 May, 2022

How Big Tech Uses Laws of UX

Table of contents


Denislav Jeliazkov
Founder @uilearn

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The biggest asset that makes me become a better designer is not by looking at dribbble, Behance, or Instagram, not even the short UI tips I see all over the internet.

I look at products and play with them to see how they do certain things either when starting up, or when hitting scale and thinking what are the design decision that went through every single one of these interactions.

Aesthetic-usability effect

Users often perceive aesthetically pleasing design as a design that’s more usable.

Humans love beauty, there is no doubt about that and this applies in design also like the user love to use eye-appealing design, that in design terms we say aesthetically pleasing design. while using an aesthetically great design users forgive minor mistakes and also love to use it.

Thus why every big app knows this therefore they make their corners rounded, icons simpler, images more attractive, text bolder, and colors sharper.

By using this ux law you can make your own design much more user-friendly and it also helps in better review of the app which in return helps you to grow.

But, only aesthetics don’t matter in long run, in the short-run users might happily ask for the help in review but after some time they’ll get frustrated and stop using your app. therefore make the app aesthetically pleasing and usable too.


  • An aesthetically pleasing design creates a positive response in people’s brains and leads them to believe the design actually works better.
  • People are more tolerant of minor usability issues when the design of a product or service is aesthetically pleasing.
  • Visually pleasing design can mask usability problems and prevent issues from being discovered during usability testing.

Law of Prägnanz

People will perceive and interpret ambiguous or complex images in the simplest form possible because it is the interpretation that requires the least cognitive effort of the user.

Making things simpler is not a new thing, we all love simpler things in real life. humans don’t like complex things, because users are also from the earth they also like simple and straight things like the simple interface, simple icons, simple colors, simple stuff as well as usable.

If you put complex things the brain basically translates those things into their simpler version just like our brain does with the moon, as the moon has rocks and bumps but our brain translates it into a smile.

The best thing to do is to just use simple stuff, learn from Spotify, the first use little complex icons which can overwhelm users, therefore, they updated their tab bar with new icons. they also make things simpler by adding various options inside one like browse and search option (old) to search (new).


  • The human eye likes to find simplicity and order in complex shapes because it prevents us from becoming overwhelmed with information.
  • Research confirms that people are better able to visually process and remember simple figures than complex figures.

Fitts Law

The time to acquire a target is a function of the distance to and size of the target.

Do you know? why the buy now, book now, shop now, add to cart, shop now, buttons are bigger than usual buttons in every app? the answer is Fitts Law.

Fitts Law explains that the time requires to get something is directly relational to the distance and the size of the element. If the target or button is small the user will take time to take action which might change the mood of the user and can result in the loss of the target.

Therefore, it is recommended that you should place your target where the user can easily click it in a very short span of time. For Example, Air BnB uses this law by placing the button too close to the thumb so that the user can easily tap on the button without taking too much time.

Uber uses it, Amazon uses it, Nike uses it, Lyft uses it, and many of them use it in their own way. You can use different colors, sizes, and icons to make the button stand out and let your user tap it as easily as possible.


  • Touch targets should be large enough for users to accurately select them.
  • Touch targets should have ample spacing between them.
  • Touch targets should be placed in areas of an interface that allow them to be easily acquired.

Jacob’s Law

Users spend most of their time on other apps. This means that users prefer your app to work the same way as all the other apps they already know.

Jacob’s law is the useful one, all the apps I used or you’re using have many (not one) things common in them. it can be tab bars, icons, styling, typography, etc. these are not coincidences they’re planned. the big apps know this law, as the user spends most of the time on other apps, therefore, making your app look similar to it ( in terms of basics) for ease of use.

Pinterest, TikTok, Instagram have their tab bar kind of similar as they are social media platforms and any user who spends most of the time on Instagram can easily use the tab bar on TikTok and Pinterest because the home, search, notification, profile tab are similar.


  • Users will transfer expectations they have built around one familiar product to another that appears similar.
  • By leveraging existing mental models, we can create superior user experiences in which the users can focus on their tasks rather than on learning new models.
  • When making changes, minimize discord by empowering users to continue using a familiar version for a limited time.

Goal-Gradient Effect.

Zeigarnik: People remember uncompleted or interrupted tasks better than completed tasks.

Goal-Gradient: The tendency to approach a goal increases with proximity to the goal.

People don’t like to finish things incomplete (most of the time) as if you aren’t doing the things you have to do, your brain recalls that process until you finish it. This is why addictions are not easy to stop.

Designers use this as a part of the design to make users stick to the app for better engagement and returns.

Pinterst uses the line that indicates how much the process is left which makes the user easily do the task as a user knows he has to take only 3 steps. if you didn’t provide it user might think there are many and can close the app for later.


  • The closer users are to completing a task, the faster they work towards reaching it.
  • Providing artificial progress towards a goal will help to ensure users are more likely to have the motivation to complete that task.
  • Provide a clear indication of progress in order to motivate users to complete tasks.
  • Invite content discovery by providing clear signifiers of additional content.

Peak-End Rule & Serial Position Effect

Peak-End Rule: People judge an experience largely based on how they felt at its peak and at its end, rather than the total sum or average of every moment of the experience.

Serial Position Effect: Users have a propensity to best remember the first and last items in a series.

These Laws explain two different things but apps use them together. They explain that the user judges anything according to their peaks and ends not by their averages, the user best remembers first and last things.
Many apps use these laws by adding important stuff inside the first and last screens and adding not so important but useful stuff in middle.

For Example, Duolingo uses the cool mascot (Owl) and illustrations for making the starting and ending awesome. Duolingo also adds illustrations inside the task to make you engaging. You can also use something like that or a thing of your own which your audience would love to see.


  • Pay close attention to the most intense points and the final moments (the “end”) of the user journey.
  • Identify the moments when your product is most helpful, valuable, or entertaining and design to delight the end-user.
  • Remember that people recall negative experiences more vividly than positive ones
  • Placing the least important items in the middle of lists can be helpful because these items tend to be stored less frequently in long-term and working memory.
  • Positioning key actions on the far left and right within elements such as navigation can increase memorization.

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