How to Enable Full 120Hz ProMotion Scrolling in Safari
If you’ve invested in a ProMotion-capable Apple device, you expect consistent high-refresh-rate output across the board. Yet, Safari often feels sluggish compared to the snap of the home screen or the fluidity of third-party browsers like Chrome. This isn't a glitch—Apple intentionally caps Safari’s rendering at 60Hz. While the official line is "energy efficiency," the reality often comes down to aggressive thermal management; keeping the GPU from ramping up prevents the device from getting warm during long browsing sessions.
Fortunately, Safari 26 (released in late 2025 with iOS 26 and macOS 26) retains the experimental toggles needed to bypass this restriction. By adjusting a specific feature flag, you can force Safari to match the 120Hz capabilities of your hardware.
Hardware and Software Requirements
To see any benefit from these changes, you must be using a device with a ProMotion display. This includes the iPhone 13 Pro or newer, any iPad Pro from 2017 onwards, and 14-inch or 16-inch MacBook Pros (2021+). On the software side, ensure you are updated to at least iOS 26.2 or macOS 26.1, as these versions stabilized the rendering flags discussed below.
A note on power consumption: Expect a hit to your screen-on time. Running the GPU at double the cadence isn't free. If you spend your day scrolling through media-heavy sites, the increased power draw will be noticeable.
Enabling 120Hz Rendering on iPhone and iPad
Apple buries its most impactful performance tweaks within the system settings to prevent the average user from inadvertently tanking their battery life. For those seeking maximum responsiveness, the path is hidden under the Advanced menu.
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Open Safari Settings: Go to Settings > Apps > Safari.
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Enter the Lab: Scroll to the bottom, tap Advanced, and then select Feature Flags.
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Kill the 60fps Cap: This list is extensive. Use the search bar at the top to find a flag titled prefer Page Rendering Updates near 60fps.
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Toggle it OFF: By disabling this flag, you remove the instruction that tells Safari to prioritize a lower frame rate.
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Hard Restart Safari: The change won't take effect until the process is killed. Swipe up to the App Switcher, toss Safari away, and relaunch it.
To confirm the change, head over to a site like TestUFO. If the flag is successfully disabled, your frame counter should finally hit the 120fps mark during active scrolling.
Activating 120Hz Rendering on macOS
On the Mac, the process is slightly more involved because you first have to expose the developer tools that Apple hides by default.
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Unlock Developer Tools: Launch Safari, go to the Safari menu in the top bar, and select Settings. Navigate to the Advanced tab and check the box at the bottom for Show features for web developers.
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Access Feature Flags: You’ll see a new Develop menu in your Mac's top bar. Click it and select Feature Flags.
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Filter and Adjust: Type "60" into the search field. Uncheck the box for prefer Page Rendering Updates near 60fps.
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Relaunch: Completely quit Safari (Command + Q) and restart it to initialize the new rendering parameters.
Troubleshooting and Maintenance
If the scrolling still feels limited, check your battery settings. Low Power Mode is a global override; it caps the display at 60Hz regardless of what your browser flags say. If your device is running hot from fast charging or heavy background indexing, the system may also temporarily throttle the refresh rate to manage thermals.
Missing Flag? If you cannot find this specific flag, you are likely on an older build of Safari. This rendering toggle became a standard experimental feature in the late 2025 software cycle.
Reverting Changes: If you notice unusual page glitches—such as "tearing" on certain video-heavy sites—return to the Feature Flags menu. On iOS, you can use the Reset all to default button at the bottom of the list. On macOS, simply re-check the box. Keep in mind that major point updates (like a move to iOS 26.3) may reset these experimental flags to their default "On" position, so you may need to re-apply this fix periodically.
