Scaling React Native apps for Tablets
Lets make your React Native app look good on Tablets
If you’ve ever worked on a React Native app then you must’ve wondered how do I make this look good on Tablets. Worry not. This tutorial will teach you how to make your React Native app not look weird on Tablets or lets say any other device.
When you make a React Native app, you just make it to work on Mobile Phones. The problem occurs when you try to make it work on Tablets. The reason is Tablets have more pixels than Mobile phones. So whatever dimensions you specify for Mobile are definitely not going to work for Tablets. In short, the bigger your device gets, the more pixels it will have.
From the docs,
All dimensions in React Native are unitless, and represent density-independent pixels. Setting dimensions this way is common for components that should always render at exactly the same size, regardless of screen dimensions.
I created a simple Chat App for this tutorial which already looks good on Mobile & we will learn how to scale the app to make it look good on Tablets.
🔗 The complete source code can be found here.
Following picture shows how the App looks when you see it on Mobile (iPhone X) & when you see it on Tablet (iPad Air 2) —
As seen above, the app on Tablet looks very small than on Phone. So we need to scale it to look good on Tablet as well.
Scaling with Flex
Flexbox is helpful while scaling. But, flexbox only scales throughout the entire width or height of the container it is in. It keeps the same proportions among different devices.
Flexbox can scale well if we add some hacks by introducing more containers but its a lot of work.
flex is limited to certain properties like
padding. But we can't use it for some other properties like
lineHeight or SVGs.
Scaling with Percentages
We can scale our app well using Percentages (%).
React Native v0.42 & above has added support for Percentages (%) but it is only limited to the properties like
Other properties like
lineHeight don't work well with percentages.
Scaling with a Library
React Native Size Matters is a library written by Nir Hadasi which helps us make our scaling easier by providing 3 simple utility functions.
The library is very small & it contains 3 simple utility functions namely —
scale(size: number)— Returns linear scaled result of the provided size, based on your device's screen width.
verticalScale(size: number)— Returns linear scaled result of the provided size, based on your device's screen height.
moderateScale(size: number, factor?: number)— Returns non-linear scale based on a resize factor (defaults to 0.5). If normal
scalewill increase by +2X,
moderateScalewill only increase it by +X.
It has some Guideline sizes which are based on ~5" screen mobile devices that makes it easy to scale for bigger devices.
It also has a
ScaledSheet method which is a scaled
It uses the following API —
moderateScalefunction with resize factor of 0.5 on
moderateScalefunction with resize factor of factor on
Chat App Demo
Now we’re going to use
react-native-size-matters in our Basic Chat App.
We’re going to build a simple Chat Wrapper (the one with Yellow & Blue Background) using
As you can see the only thing we needed to change was
fontSize to scale it well across different devices.
The way I like to scale is always try Flexbox in the beginning. Then I try to use Percentages wherever possible. Later, I try to scale the
height property vertically using
<size>@vs & for everything else I use either
The example provided in the repo is a little different as I’ve abstracted the common part into a wrapper to make the code more readable. It also has a switch to check how the App would look if
react-native-size-matters is not enabled.
The final solution after applying scaling looks like —
You can scan the following QR code to run this app if you have the expo.io client installed on your Android or iOS device:
Have more questions about scaling React Native apps?
Hit me up on Twitter! Don’t be shy to Say Hi 😃