It’s not just the best android phones which have fast displays these days. Most mid-range and high-end Android phones have a display with a refresh rate above 60 Hz, and this is true even for many budget phones. However, most of these phones only refresh at a few fixed rates, such as 60Hz, 90Hz or 120Hz, because their displays do not support variable refresh rate (VRR) technology. Some phones have VRR-capable screens, but it turns out that Android itself had no real VRR support — at least not until now.

According to Google, Android 15 is the first version of Android to support it adaptive refresh rate (ARR), which is synonymous with variable refresh rate. Before Android 15, the operating system was supported multiple refresh rates by switching the refresh rate. Basically, the OS would tell the display to switch between the different display modes it supports, such as 1080p@60Hz and 1080p@90Hz. It would try to do this intelligently, of course, by keeping track of what kind of view is displayed, but it was never really adaptive. However, with the introduction of adaptive refresh rate in Android 15, the refresh rate can not only adapt to the frame rate of the content, but also change the refresh rate in a single display mode.

Google says the adaptive refresh rate feature in Android 15 has two main benefits. First, it reduces power consumption by allowing devices to “operate at rates lower than their maximum refresh rates, switching to higher rates only when critical to the user experience, which minimizes unnecessary power consumption.” Second, ARR improves performance by eliminating the need to switch display modes, which Google says is a “known cause of jank.”

I’m sure some of you are wondering if this adaptive refresh rate feature is actually new. After all, the smartphone companies have been making propaganda variable refresh rate as a basic input-enabled feature Show LTPO for years, so what gives? Of course, I’m not very well versed in display technology, but I understand that even these devices have never supported true VRR on Android, as PC gamers are familiar with. Android devices with LTPO OLED displays, for example, can’t synchronize their displays’ refresh rates with games like many PCs do.

Instead, introducing LTPO backplanes to OLED screens simply made it more energy efficient to drive those OLED displays at lower refresh rates. This allowed Android devices with LTPO OLED panels to run at 1Hz or even 10Hz when needed, widening the range of available refresh rates. However, these refresh rates were still tied to discrete display modes that were switched by Android through the Hardware Composer (HWC) hardware abstraction layer (HAL), which in turn made calls to the lower level display. Therefore, even on devices with a true VRR/ARR panel, the Android OS would still change the refresh rate by changing the display mode.

According to the display analyst Dylan Ragasome Android devices can already change refresh rates in the same display mode, but their OEMs had to implement support for this at the kernel level. The problem with this approach is that each OEM would have to write their own logic for when to drop the refresh rate. This is challenging not only because of Android Generic Kernel Image requirements, but also because the kernel has less information than the operating system about exactly what content is being displayed.

That’s why Android 15 implementing proper VRR/ARR support at the HAL level is important, as it provides a unified way to reduce the refresh rate using information and hints that are more readily available to the OS. However, to enable VRR/ARR, OEMs must not only support the necessary kernel and system changes on devices running Android 15 or later, but also implement version 3 of the HWC HAL APIs.

I don’t know which, if any, devices running Android 15 support adaptive refresh rate, but I know some devices already support version 3 of the HWC HAL. Google Pixel 7 and later, as well as Qualcomm Snapdragon 8 Elite powered phones, have the updated HWC HAL version, while Google Pixel 6 series and Qualcomm Snapdragon 8 Gen 3 powered phones do not. It is likely that many phones receiving an OTA update to Android 15 will not receive support for the updated HWC HAL due to the effects Google Requirements Freeze (GRF) program, but even if they do, there’s no guarantee they’ll support Android 15’s adaptive refresh rate feature.

When this adaptive refresh rate feature is enabled on Android devices, it will hopefully result in more apps using lower refresh rates. An example presented by Dylan Raga is how most Android phones currently sit at 60Hz instead of 30Hz or 24Hz when playing a movie, something this feature could fix. Unfortunately, this feature is unlikely to bring the game’s PC-like refresh rate sync to Android, as Google’s documentation notes that this feature only allows the panel to work at refresh rates that are “break effect dividers (TE) of the panel”. Hopefully Google shares more details about this feature and reveals if it’s enabled on any of its existing Pixel devices, as it’s long overdue.