The short answer is, “I don’t know”, but consider where the modern smartphone is today, what it does, and what may it become, results in a few very important points to consider when trying to predict what will come next.

  1. The screen is still the most important user interface: Yes, voice assistants have improved over the years, providing a quick way to perform certain tasks, but visual information displayed on the screen remains the primary interface for running apps, consuming information and playing games. The screen is so important to a smartphone that it is one of the few consumer items that has grown larger over time (of course the other item, flat screen televisions, have become larger as prices have dropped, but, not coincidentally, those are screens, too). Smartphone screens likely will not grow too much beyond the 5.5 inch or 6 inch sizes given usability and portability concerns – it is a telling sign when companies such as Samsung have found ways to shrink the overall smartphone size while maintaining the display size by using curved edge screens and minimizing bezel widths.
  2. The integrated functions of a smartphone have marginalized entire device classes: Portable media players, point-and-shoot still/video cameras, GPS navigation devices, and, let’s not forget phones, formerly represented separate device categories. While these items can still be purchased as discrete items, the market for these single-function devices have collapsed in the face of improved smartphone capabilities. It would be hard to imagine that any of these separate device markets will ever see growth again. In fact, technology improvements in processor efficiency and solid-state storage capacity will enable the integration of additional capabilities, such as augmented reality (AR) and advanced imaging functions.
  3. The smartphone is THE connected device: The fact that smartphones provide nearly always-on access to the internet through cellular and WiFi means that all the integrated functions in a smartphone are also always connected. This level of connectivity has enabled the growth of communication services far beyond traditional email and web browsing, such as messenger apps, social media, live broadcasting, and control over connected devices in the home. Even if traditional notebook PCs gained integrated cellular capabilities, many users would likely avoid having to pay for another monthly data plan for a PC, especially as smartphones already provide WiFi-to-cellular tethering for PCs when connectivity is needed in a pinch.
  4. On an important side note, battery life remains a constant design constraint. The requirement for relatively large screen sizes (5 to 6 inches) and improved processor performance, despite power efficiency gains coming from smaller process nodes and multi-core designs, will always challenge the power budget of a device that must last at least through an entire day of normal usage. Ultimately, device size will be dictated by screen size and power requirements of the functions included, which, in turn, dictates the battery size for the given battery chemistry and runtime requirements.

Devices introduced since the advent of the modern smartphone have either been in-between type devices – think tablets that neither replace PCs or smartphones – or add-ons and accessories – think wearables or so-called smart home speakers and devices. Nothing over the past 10 years has managed to replace the smartphone, but, instead, smartphones have become so much more capable and indispensable. So, what will eventually replace your smartphone? Maybe technology evolves in a way that obviates the need for large screens, and connected integrated functions. Or, possibly, the smartphone becomes another device like the radio, television and PC – we may always have some or all these items at our disposal, but something else will come along to become another must-have to add to the pile.