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Mobile App Form Factors: What You Need to Know

Mobile app form factors can make for a serious hurdle for mobile app development, especially during testing. What's there to do about it?

When planning a mobile app development project, team members often become overly focused on matters such as the operating system they should use and the devices (Apple, Android, etc.) they’ll be developing for.

While these are certainly important aspects, you must also consider which mobile app form factors you want your project to support, for if you launch your solution on the wrong combination of app form factors, you may inadvertently be neglecting a huge segment of your target market. Conversely, wasting precious DevOps resources configuring an app for a less popular form factor can cause you to go over budget or fall behind schedule. 

To help you navigate and combat these software development challenges, let’s dive deeper into what app form factors are and why you need to be cognizant of them during DevOps processes. 

What are mobile app form factors?

A form factor refers to the “size, configuration, or physical arrangement of a computing device.” As it pertains to a mobile app, form factors typically refer to the layout and screen size that the application is configured to support. 

The app form factor for a phablet, for instance, will be different from that of a small smartphone with a screen size of 3.5 inches or less. A mobile app designed to function on a small phone will not perform as intended on a phablet or tablet.

However, that does not mean that you will need to accommodate all app form factors when planning your project. When deciding which to support, you should consider usage trends amongst your target audience, as well as general adoption trends.

Suppose that the majority of your audience uses small and average-sized smartphones, as well as phablets, but only about 5% of your user base owns a tablet. In such a scenario, you may decide that supporting the tablet form factor is not a wise use of your time or resources. 

Five types of app form factors

Generally speaking, mobile app form factors can be grouped into one of five categories. They are as follows:

  • Small phones: A smartphone is considered to be small when it has a screen of 3.5” or smaller. They are a favorite among users who do not want to tote around a bulky, cumbersome device.
  • Medium phones: As the category includes the standard iPhone and Samsung Galaxy, the majority of today’s smartphones are considered medium phones, given that they have screens ranging in size from 3.5 to 4.9 inches. 
  • Phablets: Phablets are much larger smartphones that fill the void between medium/standard-size devices and small tablets, such as the Kindle Fire. Typically, phablets have screens ranging between 5 and 6.9 inches.
  • Small tablets: Small tablets have screen sizes measuring between 7 and 8.4 inches and are quite popular due to their portability and relatively low price points.
  • Full-size tablets: The iPad is the best-known example of a full-size tablet. With screen sizes of 8.5” or larger, these devices require specially configured applications. 

Over the last few years, a new category of mobile app form factors has emerged thanks to the development of foldables. Applications that run on these devices must support both a standard smartphone form factor, as well as that of a phablet or small tablet. While foldables add a new layer of complexity to DevOps processes, they also provide developers with opportunities to innovate their design techniques.

Illustrations of a variety of tools
Different form factors can require different approaches. Image: Sofy x Ctrl-x, Shutterstock

How app form factors are evolving

Mobile devices and app form factors are evolving. This is being driven by two things: device innovation and changes to consumer habits. The three types of devices that currently have the most notable impact on app form factors include the following:


When they first hit the market, many saw phablets as a bit of an anomaly. For years, manufacturers were striving to downsize their mobile devices to increase portability, but as smartphones became more advanced, forward-thinking developers saw an opportunity to give users exactly what they wanted — huge screens. 

According to some experts, phablets have the potential to make up nearly 75% of the smartphone market within the next five years. While there is a chance that consumer preferences may shift again, its wise to address phablet app form factors during DevOps processes based on the market’s current trends. 


By 2031, the foldable smartphone market is projected to reach a value of $64 billion. This translates to a compound annual growth rate (CAGR) of 25.2%. 

However, while experts have a positive outlook on the foldable market, current usage levels don’t quite support such conclusions. In 2021, foldable smartphones accounted for only about 0.5% of new sales. By 2025, that figure is only expected to increase to about 2%.

That said, your team should consider incorporating foldable app form factors into its development workflow. If the trend does catch fire, as experts predict, you will be a step ahead of the competition. 


Tablets are by no means a new development, but the tablet market is still going strong. Both full-size and compact tablets remain incredibly popular among users, even though they can now use many of the same applications on their handheld devices. In Q1 of 2023 alone, Apple shipped out 10.8 million iPads, and more economical options, like Amazon’s Kindle Fire, consistently sell millions of units each year as well. 

While you can certainly tap into a healthy market of app users by addressing your mobile app form factors, adding tablet compatibility to the mix is a smart move if you want to maximize adoption rates. 

Why test various app form factors?

With real device testing, your team runs your application on a variety of different devices and OS versions to ensure that it functions properly across a broad range of devices and software. 

The same underlying principle supports the need for extensive mobile app form factor testing. Just because your app performs flawlessly on a standard smartphone does not mean it will function equally as well on a phablet or tablet. In fact, it probably won’t. 

To support several mobile app form factors, you need to create multiple configurations of your project. Even if you use the same framework for each configuration, altering the display and layout of the app can cause bugs or glitches. Form factor testing gives you the opportunity to detect and correct these shortcomings before they negatively impact the user experience. 

Optimize your project for multiple app form factors

It’s difficult to overstate the importance of testing your software across multiple app form factors. By thoroughly testing your app on several form factors and making it available to a wider range of users, you can maximize your reach and connect with more consumers. 

That said, testing on several different app form factors can be a complex, time-consuming endeavor. In order to avoid major delivery delays while still engaging in adequate testing, you must invest in quality automated testing tools. Automating core testing processes and leveraging no-code solutions will enable your team to increase their efficiency while also testing apps more thoroughly. 

Elevating your testing capabilities and incorporating multiple mobile app form factors will enable you to deliver a better user experience and make your app stand out in the crowded marketplace. 

Disclaimer: The views and opinions expressed above are those of the contributor. They do not necessarily represent or reflect the official beliefs or positions of Sofy.