Performance
Sleeping tabs, energy saver, and loading pages before you open them.
Settings → Performance holds everything that trades memory, battery, and speed against each other. The defaults suit most computers. Change them if your fans spin up, your battery runs down, or you want pages to open faster.
Presets
Start from a preset, at the top of the page, sets a handful of the page's settings at once:
| Rich | Balanced | Lean | |
|---|---|---|---|
| Sleep background tabs | After 2 hours | After 1 hour | After 15 minutes |
| Preload pages | On | On | Off |
| Preload links on pages | Load ahead | Connect early | Off |
| Live previews | All three | Typed sites and current tab | None |
| Energy saver | Battery at 10% or lower | Battery at 20% or lower | When on battery |
| Animations | Always | System | Off |
A preset isn't a mode. Every setting stays free to change afterwards, and the page says Custom setup once yours no longer matches one. Each preset's menu has Undo last preset, which puts back what the last one changed.
Right now shows how much memory the browser is using across every window, with how many tabs are loaded or asleep and how many extensions are on.
Sleeping tabs
A sleeping tab keeps its place, its title, and its snapshot in the command center, but its page is unloaded to free memory. It reloads when you go back to it. Tabs playing sound never sleep.
In Settings → Performance → Tabs:
| Setting | What it does |
|---|---|
| Sleep background tabs | A tab left unused this long goes to sleep. Never, or after 15 minutes up to 6 hours. The default is 1 hour. |
| Close unused tabs | When you come back to the browser, tabs you haven't looked at in this long close, with Undo. Pinned tabs, tabs in folders, and tabs playing sound stay open. Off by default. |
| Sleep tabs when memory runs low | When your computer runs short of memory, background tabs sleep one at a time, the heaviest first, until there's enough. Tabs you used in the last few minutes go last. On by default. |
| Warn about heavy tabs | A background tab using a lot of memory or CPU for a minute gets a notice at the top of the page, with Sleep tab. On by default. |
| Sleep background tabs now | Sleeps every tab that isn't on screen, playing sound, or loading, right away. |
Sleeping a tab yourself
- Right-click a card in the command center or on the home page and pick Sleep tab. A split's card offers Sleep 2 tabs.
- The command center's Sleep other tabs button sleeps everything but the tab you're on.
- The titlebar's browser menu and the wheel have Sleep tab too.
You can sleep the tab you're on. The window moves to the tab you'd land on if you closed it, and the tab sleeps once it's off screen. Sleep tab has no keys by default; give it some in Settings → Keyboard shortcuts.
How a sleeping tab's card looks is up to you. See Command center layouts.
Energy saver
Energy saver does less in the background to save battery, like Chrome's. While it's on, an Energy saver chip shows in the titlebar. Press it for a menu that says what turned it on, with Turn off for now.
⌘Ctrl⌥AltE turns it on or off from anywhere. You can change or clear that key in Settings → Keyboard shortcuts.
Settings → Performance → Energy saver → Turn on decides when it starts by itself:
| Choice | When |
|---|---|
| Never | Only when you turn it on yourself |
| When on battery | Whenever the computer is unplugged |
| When battery is low | At 10%, 20% (the default), 30%, or 50% or lower, on battery |
| Always | All the time |
Turning it off for now lasts until you plug in or unplug. Some computers don't report their battery level; on those, When battery is low never turns on by itself, and Settings says so.
What it does, each with its own switch:
- Sleep background tabs sooner: tabs out of sight for 10 minutes go to sleep, even if Sleep background tabs is set longer or to Never.
- Freeze background tabs: tabs out of sight for 5 minutes stop running scripts and timers until you go back to them. Tabs playing sound or being shared keep running.
- Stop preloading: links on pages and the command center load only when you open them.
- Turn off animations: the browser's own motion stops. Your Animations setting comes back when energy saver turns off.
Energy saver also stops the command center's live previews.
Preloading
Preloading starts work on a page before you open it, so it appears sooner. It lives in Settings → Performance → Preloading.
Preload pages covers the command center. While you type, the site Enter would open is connected to early, and sites you visit most start loading before you press Enter. A sleeping tab whose card you rest the pointer on wakes, so it's ready when you open it.
Preload links on pages covers links inside web pages:
| Choice | What happens when the pointer rests on a link |
|---|---|
| Off | Nothing. Links load when you click them. |
| Connect early (default) | The browser connects to the link's site, so the page starts sooner. Nothing is downloaded. |
| Load ahead | A link to the same site also downloads its page, so it opens almost at once. Other sites are only connected to. |
Wait on a link sets how long the pointer has to rest first, from 65 ms to 400 ms (100 ms by default). Pressing a link always starts it. Add a site to Never preload on to leave it out, subdomains included.
Links that sign you out, delete something, unsubscribe, or are part of a sign-in are never preloaded, since loading them early could act on them. Incognito windows never preload links.
Background tabs wait to play
A link you open in a background tab loads right away, but video or music on it waits until you first look at the tab. Pressing play on it from its card or the Dynamic Island still plays it.
Live previews
The command center can show some cards as live video instead of a still snapshot. Find the switches in Settings → Performance → Live previews, or in Settings → Tab dialog → Cards:
- Live preview of typed sites: an address you type loads ahead and shows live in a Preview card at the front of the grid. Enter opens it without loading it again. If a tab is already open at that address, its card leads instead and Enter goes to it. Needs Preload pages.
- Live current tab: the current tab's card plays what its page shows, up to 30 frames a second.
- Live preview on hover: resting the pointer on a card plays that tab live too. Sleeping tabs keep their snapshot.
A tab playing video keeps its snapshot, since capturing it would make the video stutter. All three are off while energy saver is on.
Graphics
- Use hardware acceleration when available draws pages with your graphics card. Turn it off only if pages flicker or go black.
- Keep drawing when covered keeps a window drawing while another window covers it. Turn it on if you share the browser's window in Discord or OBS and the stream freezes or goes black when something's in front of it. Off by default, which saves battery.
Both need a restart, and the section offers one when you change them.
Animations
Settings → Performance → Animations is the same setting as Settings → Appearance → Motion: System follows your computer's reduced-motion setting, Always animates regardless, and Off switches tabs at once and shows panels in place.