Enable Smoother 120Hz Browsing in Safari

[MacRumors]

Any iPhone, iPad, or Mac with a ProMotion display is capable of rendering buttery smooth 120Hz animations. However, Apple's Safari browser is locked to 60fps page rendering by default, making scrolling feel noticeably choppier for some users than in Chrome or Firefox. Thankfully, recent versions of Safari include a hidden setting that lets you unlock 120Hz rendering.

At 60Hz, your screen refreshes every 16.7 milliseconds, meaning each frame of a scrolling page stays on screen for that duration. At 120Hz, the refresh interval drops to 8.3 milliseconds, so the image updates twice as often. This reduces the perceived blur and judder as content moves across the screen, making motion look more fluid and responsive. For a better idea of the difference, visit Blur Buster's Motion Tests webpage and watch the refresh rate test in Safari.

The difference is most noticeable when scrolling text-heavy pages or panning across detailed content. That said, the improvement is more dramatic for some people than others. If you've never noticed Safari feeling "off" compared to other apps, you may not register much difference. But if you've used Chrome or Firefox on the same device and wondered why Safari felt slightly sluggish, this is the reason.

The 120Hz option is buried in Safari's Feature Flags, a developer-focused menu that doesn't require any special mode to access on iPhone or iPad. On Mac, you'll need to enable developer features first, but it's a straightforward process. Keep in mind that turning on 120Hz may impact your device's battery life if you tend to browse a lot.

Here's how to enable 120Hz scrolling on all your Apple devices.

Enable 120Hz Safari Browsing iPhone and iPad

1. Open the Settings app.
2. Scroll down and tap Apps.
3. Tap Safari.
4. Scroll to the bottom and tap Advanced.
   
   
   
   Tap Feature Flags at the bottom of the list.
5. Scroll to Prefer Page Rendering Updates near 60fps and toggle it off.
6. Force quit Safari and reopen it.
   
   

With this setting disabled, Safari will now render pages at up to 120Hz on ProMotion-equipped devices, including iPhone 13 Pro and later, and iPad Pro models with ProMotion.

Enable 120Hz Safari Browsing on Mac

Enabling 120Hz on Mac requires a few extra steps to reveal the Feature Flags menu.

1. 
   Open Safari, then click Safari in the menu bar and choose Settings....
   
   
   
   Click the Advanced tab.
2. At the bottom of the pane, check the box next to Show features for web developers.
   
   
   
   A new Feature Flags tab will appear in the toolbar – click it.
3. In the search field at the top right, type 60fps.
4. Uncheck Prefer Page Rendering Updates near 60fps.
   Quit Safari completely and reopen it.
   
   

This works on any Mac with a ProMotion display, which includes the 14-inch and 16-inch MacBook Pro models introduced in 2021 and later. If you have external displays connected to your Mac that are capable of refreshing at 120Hz, they should also benefit from the change.

Kudos goes to MacStories for unearthing the 120Hz scrolling tip recently shared by developer Matt Birchler.

Article Link: Enable Smoother 120Hz Browsing in Safari

 

[johannnn]

Why is this disabled by default?

 

[HouseLannister]

Why is this disabled by default?

Battery life. Most people don't need 120hz to read static webpages.

 

[cbcasas]

If this is hidden by default I wonder if it murders your battery

 

[jrath1]

Safari is such a garbage browser. This buried setting is just another example.

 

[strkt1192]

Lmao recently discovered. This has been known for like 2 years

https://www.reddit.com/r/iphone/comments/1gzltgr/guide_how_to_enable_120hz_in_safari

https://www.reddit.com/r/MacOSBeta/comments/149couv/sonoma_safari_120hz

 

[apple contributor]

Whoa, I feel the difference, didn’t notice before

Why is this disabled by default?

According to Google, it’s to ensure stability of complex websites, and saving battery power

 

[apple contributor]

If this is hidden by default I wonder if it murders your battery

it eats up 15-20% of your battery… according to reddit😅

 

[bg1419]

I can usually tell a difference between 60 and 120, it’s easy to compare on the Home Screen or other apps by toggling low power mode. But in safari I’m not seeing a difference regardless of how I have this setting set; are we’re sure we know how this “feature” works? The toggle says “prefer,” not force. I wonder if someone at macrumors was just poking around in settings and saw this, and wrote an article assuming they knew what it meant. I’d like to see some documentation from Apple explaining it because my eyes aren’t seeing the difference

 

[dannyyankou]

This is a great way to destroy your battery life, if you want to.

120hz for just scrolling webpages is not noticeable enough and not worth the trade off of battery life.

 

[TooMuchPhone]

This is probably just for animations on web pages and NOT scrolling

 

[jkool]

If this is hidden by default I wonder if it murders your battery

The game is afoot, Watson!

 

[ProbablyDylan]

I wonder what the need for this is. ProMotion is supposed to adjust the screen refresh rate and framerate to match the motion happening on-screen, increasing to smooth out animations and reducing when nothing is happening to conserve power. Does that feature not work as intended?

 

[MacFan782040]

Is battery life really that much worse?

 

[SDAVE]

This is probably just for animations on web pages and NOT scrolling

Its for both

 

[kkillam]

Good tip, one that I didn’t actually know already.

 

[Spinarelo]

OMG I can't believe I didn't know this.. always felt like the webpage scrolling was much smoother in chrome on my work phone (galaxy s25) now it feels the same on my iPhone. Glorious tip! Thank you MR

 

[ShivneelSingh]

OMG thank you so much for this tip!!
This is super helpful, especially on Tahoe, which is an absolute mess for me.

 

[novagamer]

Safari has a variable refresh rate on modern devices but it does not always hold it until scrolling finishes, the end of scrolling text is often quite juddery without this disabled. It's extremely obvious on some mobile devices, newer Macs are fine.

Good post, even if the toggle is years old.

See old thread: https://forums.macrumors.com/threads/enabling-120hz-scrolling-in-safari.2323961/

If you're on a fast mac this basically will speed up your animation speed any scrolling differences are a placebo. Use Quartz debug if you question this.

 

[roncron]

I didn’t know about this. Followed the instructions and I notice a difference. It’s not night and day, but it’s nice.

But if my battery life drops noticeably with this setting change, I’m happy to go back.

 

[TooMuchPhone]

Its for both

Promotion scrolls very smooth on my m5 while 60hz does not (this is without changing the setting in the article). Therefore I do not think it adjusts scrolling, at least on some configurations.

 

[MikeZTM]

I can usually tell a difference between 60 and 120, it’s easy to compare on the Home Screen or other apps by toggling low power mode. But in safari I’m not seeing a difference regardless of how I have this setting set; are we’re sure we know how this “feature” works? The toggle says “prefer,” not force. I wonder if someone at macrumors was just poking around in settings and saw this, and wrote an article assuming they knew what it meant. I’d like to see some documentation from Apple explaining it because my eyes aren’t seeing the difference

This is only for JavaScript animations on the webpages, not for scrolling.

Scrolling always use 120fps regardless of this flag.

 

[Spinarelo]

Is battery life really that much worse?

Probably not, but the internet hysteria mob will tell you it's the worst thing ever for your battery

 

[Dust-by-Monday]

Scrolling is exactly the same for me. No difference.

 

[Channan]

I can usually tell a difference between 60 and 120, it’s easy to compare on the Home Screen or other apps by toggling low power mode. But in safari I’m not seeing a difference regardless of how I have this setting set; are we’re sure we know how this “feature” works? The toggle says “prefer,” not force. I wonder if someone at macrumors was just poking around in settings and saw this, and wrote an article assuming they knew what it meant. I’d like to see some documentation from Apple explaining it because my eyes aren’t seeing the difference

Yeah I just did this on my M4 iPad Pro and don’t notice a difference. Then again, I’m also one that doesn’t mind the 60 Hz iPad mini display and don’t feel like I’m missing out not having ProMotion.