macOS Tahoe is Apple's 2025-26 release, and it's a significant one. It introduced what Apple calls Liquid Glass: a sweeping visual overhaul that makes windows, menus, and interface elements look more translucent and layered. It's also the last version of macOS that will ever run on Intel Macs, meaning there are no more OS upgrades coming for that hardware after this.
For most people on modern Apple Silicon machines (M2 and later with 16 GB or more), Tahoe settles into normal performance after a few days. For everyone else, it can be a noticeably heavier operating system than what came before. This guide covers the Tahoe-specific causes and what to actually do about them.
If your Mac was already slow before Tahoe, this general guide to Mac slowness is the better starting point. And if you upgraded recently and things feel slow right now, see what to do when your Mac is slow after a macOS update first.
What's new in Tahoe that might slow your Mac?
Three things stand out.
The Liquid Glass interface. Tahoe's visual redesign is beautiful on fast hardware and demanding on slower hardware. Translucent materials, blurred backgrounds, and layered window effects all run through a macOS process called WindowServer (the part of macOS that draws everything you see on screen). On older Intel chips and base 8 GB Apple Silicon Macs, this can push WindowServer harder than Sequoia did, causing choppier animations and a generally less responsive feel.
Apple Intelligence arriving on more Macs. Tahoe brought Apple's AI features to M1 machines that didn't have them before. If your Mac just gained Apple Intelligence support, you may notice new background activity as the system downloads models, indexes content, and sets things up. This usually settles after a few days but can be noticeable while it's happening.
iPhone Mirroring. Tahoe expanded iPhone Mirroring, which lets you control your iPhone from your Mac. It's a genuinely useful feature, but keeping it open in the background can cause WindowServer to use more memory than usual, especially on Macs with external displays also connected.
Common Tahoe-specific slowness issues
WindowServer using a lot of memory. WindowServer is the process responsible for drawing your screen. On Tahoe, some users have found it slowly accumulating memory over time, particularly with iPhone Mirroring active or with multiple displays. You can check this in Activity Monitor (press Command-Space, type "Activity Monitor", press Return, then click the Memory tab and look for WindowServer in the list). For a detailed look at what memory means here, see what memory pressure means on a Mac.
Animations stuttering on Intel Macs. Liquid Glass relies on compositing effects that Intel GPUs handle less efficiently than Apple Silicon. On an Intel Mac, especially one from 2018 or earlier, you may see hesitation when opening windows, switching apps, or moving through Mission Control. This isn't a bug; it's the new interface demanding more from older graphics hardware.
Sluggishness on 8 GB Apple Silicon. The base MacBook Air and entry-level Mac mini ship with 8 GB of unified memory (a single pool shared between the CPU and GPU). Tahoe's heavier visual layer eats into that pool more than Sequoia did, leaving less headroom for your actual apps. If you regularly run several apps at once, this headroom reduction is felt.
Slow first few days. Every major macOS upgrade triggers background work: Spotlight re-indexing your drive, Photos re-analysing your library, iCloud syncing, and now Apple Intelligence setting itself up. This is normal. It usually finishes within 24 to 72 hours of the upgrade. If things are slow right now and you upgraded recently, give it until the weekend before assuming the worst.
How to make Tahoe faster: the practical fixes
Wait for the x.0.1 or x.1 patch. Apple almost always ships a point release within a few weeks of a major macOS launch that addresses the most-reported performance and stability issues. If you upgraded on day one, checking for a software update and installing the latest patch is the single most effective thing you can do. Go to Apple menu › System Settings › General › Software Update.
Turn on Reduce Motion. Go to System Settings › Accessibility › Display and enable Reduce Motion. This replaces sliding and zooming animations with simple cross-fades, which are much cheaper for WindowServer to render. On Intel Macs and 8 GB Apple Silicon machines, the improvement is immediate and obvious.
Turn on Reduce Transparency. In the same panel, enable Reduce Transparency. This removes the blurred translucent effects from menus, the Dock, and window backgrounds. Liquid Glass is the most demanding part of Tahoe's visual redesign; this is the switch that turns the heaviest part of it off.
Turn off Apple Intelligence if you don't use it. Go to System Settings › Apple Intelligence & Siri and turn Apple Intelligence off. If you're not using Writing Tools, the enhanced Siri, or image generation, you're paying a background resource cost for features you're not benefiting from. Turning it off reclaims that headroom. You can always turn it back on later.
Close iPhone Mirroring when you're not using it. Don't leave it open in the background. Quit it fully (right-click the Dock icon, choose Quit) rather than just closing the window. This is especially worth doing if you're on a Mac with external displays.
Let the settling period pass. If you upgraded within the last three days, give it time. The background indexing and Apple Intelligence setup that runs after a major upgrade is temporary. Restarting your Mac once a day during this period helps macOS finish the work faster.
Should I downgrade or stay on Tahoe?
For most people, staying on Tahoe and applying the practical fixes above is the right call. Downgrading macOS is technically possible but genuinely complicated: it involves wiping your Mac and restoring from a backup taken before the upgrade, and you lose anything created since then.
There is one case where staying on an older version makes sense: if you're on an Intel Mac and Tahoe feels significantly worse than Sequoia even after turning on Reduce Motion and Reduce Transparency. Since Tahoe is the last macOS Intel will ever receive, there's no future version to hope for on that hardware. Staying on Sequoia is a reasonable decision if it served you well. You'll still receive security updates for Sequoia for a couple of years.
If you're on Apple Silicon and things feel slow, the fixes in this post should get you to a comfortable place. Apple Silicon Macs are well within their supported life, and Tahoe will only get smoother as point releases ship.
When is the slowness about your Mac, not Tahoe?
Not everything slow after a Tahoe upgrade is Tahoe's fault. It's worth checking a few things that can look like an OS problem but aren't.
Open Activity Monitor (Command-Space, type "Activity Monitor", press Return). Click the Memory tab and look at the Memory Pressure graph at the bottom. Green means your Mac has headroom. Yellow means it's working hard. Red means it's genuinely struggling. If the graph is red even after restarting and closing apps you're not using, the issue may be that your Mac simply doesn't have enough memory for the workload you're running. Tahoe didn't cause that, it may have nudged it over the edge.
Also check your disk space. Go to Apple menu › About This Mac › More Info › Storage. If your disk is more than 90% full, that alone can make your Mac feel slow regardless of the OS version. A full disk affects how macOS manages temporary files and virtual memory.
For a broader look at what else might be going on, this guide to WindowServer explains the process in plain English and how to tell when it's misbehaving versus just working hard.
Apple also maintains a support page on Mac slowness that's worth a read if you want Apple's official take alongside the fixes here.