How to Resolve Safari Memory Leaks on Mac M5?

Your shiny new Mac M5 promises speed, efficiency, and silky smooth browsing. But then Safari starts eating RAM like a hungry teenager, your fans spin up, and a pop up warns you that your system has run out of application memory. Frustrating, right? You bought premium Apple Silicon hardware to avoid this exact mess.

Safari memory leaks are not new, but they hit harder on M5 machines because users push these chips with dozens of tabs, multiple tab groups, AI tools, and heavy web apps. The good news is that most leaks have practical fixes you can apply today.

This guide walks you through every step, from quick wins to deeper system cleanups, so you can get Safari back to behaving the way Apple advertised.

Key Takeaways

• Memory leaks usually come from extensions, tab groups, or stale caches, not from the M5 chip itself. The hardware is fine; the software is leaking.
• Activity Monitor is your best friend. Always check which Safari process (Safari Web Content, Networking, Graphics) is the real memory hog before applying fixes.
• Clearing caches, website data, and favicons resolves a large share of leaks because Safari stores data more aggressively over time.
• Tab groups and pinned tabs hold memory longer than regular tabs. Closing or trimming them often gives instant relief.
• Keep macOS and Safari updated. Apple patches memory bugs in point releases like macOS Tahoe 26.x updates, so staying current matters.
• Restarting your Mac daily is a legitimate fix, not a workaround. Apple Silicon machines hold memory across sleep cycles, which lets leaks build up.

Understand What a Safari Memory Leak Actually Is

A memory leak happens when Safari requests RAM from macOS but fails to release it after the task ends. Over hours or days, this unused memory piles up. Eventually, your Mac M5 starts swapping data to the SSD, which slows everything down.

On Apple Silicon Macs like the M5, you may see “Your system has run out of application memory” even if you have 16GB or 24GB of unified memory. That message means swap has filled up, not that your physical RAM is small.

Safari has several internal processes. The main app is just a shell. The heavy lifters are Safari Web Content (one per tab or site), Safari Graphics and Media, and Safari Networking. A leak in any one of these can spiral.

You also need to know that unified memory on M5 is shared with the GPU. So when a leak spreads, your graphics performance dips too. Recognizing this helps you spot leaks before they freeze your machine.

Once you understand the source, the fixes below become much more logical. You are not chasing ghosts; you are stopping specific processes from holding memory they no longer need.

Check Memory Usage in Activity Monitor First

Before changing settings, find the real culprit. Open Activity Monitor from Applications, then Utilities. Click the Memory tab at the top.

Sort the list by the Memory column so the biggest users appear first. Look for entries that start with Safari or com.apple.WebKit. If a single Safari Web Content process is using 5GB or more, that tab or site is your problem.

Click the small arrow next to the Safari row to expand all child processes. You will see each tab listed with its URL or site name. This tells you exactly which website is leaking.

Pay attention to the Memory Pressure graph at the bottom. Green means you are fine. Yellow means swap is starting. Red means you are in trouble. If you are red while Safari is open, you have confirmed the leak.

Also check Swap Used at the bottom. A healthy M5 with 16GB should rarely exceed 2GB of swap during normal browsing. If you see 8GB or more of swap, Safari is the most likely suspect.

Write down which tabs or processes are the worst offenders. You will close them first in the next steps.

Restart Safari the Right Way

A simple quit and relaunch clears most temporary leaks. But there is a better way that prevents Safari from reopening all your previous tabs immediately, which would just reload the leak.

Quit Safari fully by pressing Command + Q. Wait five seconds. Now hold the Shift key while clicking the Safari icon to launch it. This opens Safari with no previous windows or tabs.

If Safari refuses to quit, force quit it. Press Option + Command + Esc, select Safari, and click Force Quit. On M5, this is usually instant.

After Safari opens fresh, watch Activity Monitor for a minute. Memory use should drop to under 500MB with one blank tab. If it does not, the leak source is in caches or extensions, which we will tackle next.

Make a habit of restarting Safari at the end of each workday. This stops slow leaks from accumulating overnight. It takes ten seconds and saves you hours of slowdowns later.

You can also use Activity Monitor to kill individual Safari Web Content processes without quitting the whole browser. Select the process and click the X button at the top. The tab will show a blank crash page, but other tabs stay open.

Close or Trim Your Tab Groups

Safari tab groups are convenient, but they hold memory longer than regular tabs. Even tabs you have not viewed in days may still occupy RAM, especially if they were loaded once during the session.

Open Safari and click the sidebar icon at the top left. Look through each tab group. Count how many tabs each one holds. If any group has more than 20 tabs, that is a red flag.

Right click any tab group and choose Close Tab Group. The group stays saved in your sidebar, but its tabs unload from memory. You can reopen it later when you actually need it.

For tabs you want to keep but not load, consider saving them as bookmarks instead. Bookmarks use almost zero memory. Tab groups, even closed ones, can sometimes retain cached site data.

Also review your Pinned Tabs. Pinned tabs reload every time Safari launches and stay in memory the whole session. Unpin any pinned tab you do not use daily. Right click the pinned tab and choose Unpin Tab.

If you rely heavily on tab groups for work, split them into smaller groups of 10 to 15 tabs each. Smaller groups load less data at once and recover faster after a Safari restart.

Disable or Remove Problem Extensions

Extensions are the single biggest cause of Safari memory leaks on Apple Silicon. A poorly coded ad blocker, password manager, or AI sidebar can hold gigabytes of RAM without you noticing.

Open Safari and go to Safari menu, then Settings, then the Extensions tab. You will see every installed extension with a checkbox.

Uncheck every extension. Quit Safari, relaunch with Shift held down, and browse normally for an hour. If memory stays low, an extension was the leak.

Now turn extensions back on one at a time. After each one, browse for 30 minutes and check Activity Monitor. The extension that triggers the spike is your culprit. Remove it and find an alternative.

Common offenders include older versions of ad blockers, screen recording extensions, and AI assistant extensions that inject scripts into every page. Even reputable extensions can leak if they have not been updated for the latest macOS.

To fully remove an extension, click it in the Extensions list and choose Uninstall. Safari may direct you to the App Store to remove the parent app.

Keep your extension list short. Most users only need two or three extensions. Every extra one adds memory overhead and increases the chance of a leak appearing later.

Clear Safari Cache and Website Data

Safari stores cache files, cookies, and local storage for every site you visit. Over months, this database grows huge and starts slowing memory operations.

First, enable the Develop menu. Open Safari Settings, click Advanced, and tick Show features for web developers. Close Settings.

Now click the Develop menu in the menu bar and choose Empty Caches. This clears Safari’s working cache instantly without touching cookies or logins.

For a deeper clean, go to Safari Settings, then the Privacy tab. Click Manage Website Data. You will see every site that has stored data on your Mac. Click Remove All and confirm.

This logs you out of most sites, so you will need to sign back in. The tradeoff is worth it because the memory savings can be massive. Some users report Safari dropping from 8GB to under 1GB after this step.

If you want a manual deep clean, quit Safari, open Finder, press Command + Shift + G, and go to ~/Library/Safari/. Move the Databases folder and LocalStorage folder to the trash. Safari will rebuild them clean on next launch.

Repeat this cleanup every two or three months to keep Safari lean.

Rebuild the Favicon and History Database

Safari stores favicons and your browsing history in SQLite databases. These files can become bloated or corrupted, which causes Safari to use excessive memory while reading them.

Quit Safari completely. In Finder, press Command + Shift + G and paste ~/Library/Safari/. Look for the file named Favicon Cache folder and the file called History.db.

Move the Favicon Cache folder to your desktop as a backup. Safari will rebuild it automatically and the new version will be smaller and faster.

For history, hold Option while clicking the Safari menu. The Clear History option changes to Clear History and Website Data. Choose All History from the dropdown and confirm.

This step is especially helpful if you keep months of browsing history. A large history database forces Safari to load more data into memory every time you open the browser.

If you want to keep history but rebuild the database, use the terminal. Open Terminal and run sqlite3 ~/Library/Safari/History.db "VACUUM;". This compacts the database without deleting entries.

After rebuilding, launch Safari and notice how much faster the start page and tab switching feel. Memory use at idle should drop noticeably.

Turn Off Unnecessary Safari Features

Safari includes many background features that consume memory even when you are not using them. Turning off the ones you do not need frees up RAM immediately.

Open Safari Settings. In the General tab, set Safari opens with to A new private window or A new window. Avoid All windows from last session because it reloads every leaky tab at startup.

In the Tabs tab, uncheck Show website icons in tabs if you have many tabs open. Each favicon uses a tiny bit of memory, and dozens add up.

In the Websites tab, click Auto Play on the left. Set it to Never Auto Play for all websites. Video elements running in background tabs are a top memory leak source.

Also click Page Zoom and set it to 100 percent for all sites unless you really need zoom. Custom zoom levels per site store extra data.

Disable Safari Suggestions and Preload Top Hit in the Search tab. These features fetch pages in the background and keep them in memory just in case you click them.

Turn off iCloud Tabs syncing if you do not use it across devices. Open System Settings, click your Apple ID, click iCloud, and uncheck Safari. iCloud Tabs sync can hold tab metadata in memory continuously.

Update macOS and Safari

Apple regularly patches Safari memory leaks in point updates. Running an older macOS version on your M5 means you may be missing important fixes.

Open System Settings, click General, then Software Update. Wait for it to check. Install any pending updates, even small ones labeled as security patches.

Safari updates with macOS on modern systems, so you cannot update Safari separately. Always restart your Mac after a macOS update, even if it does not require one. A fresh boot clears any leftover memory state from the old version.

Check the release notes for each update. Apple often lists fixes like “resolves an issue where Safari may use excessive memory after extended use”. These notes confirm the leak you are facing has already been patched.

If you are on a beta version of macOS, consider rolling back to the stable release. Beta builds frequently introduce new memory bugs that get fixed before final release.

Also keep your Safari extensions updated through the App Store. Open the App Store, click Updates, and install any pending extension updates. Old extensions on new macOS versions are a classic leak source.

Set automatic updates to on so you never fall behind again. Most leaks die quietly the moment you install a fresh update.

Disable iPhone Mirroring and Continuity Features

iPhone Mirroring is a popular macOS feature, but it has been linked to memory leaks on Apple Silicon Macs. It runs background processes that can interact poorly with Safari.

Open System Settings, click Desktop and Dock, scroll down, and find Widgets. Uncheck Use iPhone widgets. This stops your Mac from constantly polling your iPhone for data.

Next, open the iPhone Mirroring app and quit it from the menu bar. Then go to System Settings, click General, then AirDrop and Handoff. Turn off iPhone Mirroring entirely if you do not use it daily.

Also disable Handoff if you do not move tasks between devices. Handoff keeps a small but persistent memory footprint that grows during long sessions.

These features sound unrelated to Safari, but they share underlying frameworks. When one leaks, Safari often inherits the problem because both use the same WebKit and networking layers.

Many users on macOS Sequoia and Tahoe reported their leaks vanished after disabling iPhone Mirroring. Try this fix even if you think it is unrelated. It costs nothing to test.

If you need iPhone Mirroring, close it manually after each use. Do not leave it running in the background while you browse heavily in Safari.

Manage Login Items and Background Apps

Apps that launch at login can interfere with Safari’s memory management. Cloud sync tools, screen recorders, and clipboard managers are common offenders.

Open System Settings, click General, then Login Items and Extensions. You will see two lists: Open at Login and Allow in the Background.

Review each item. Disable anything you do not actively need. Pay special attention to browser sync tools, VPN apps, and ad blockers that work outside Safari. These often have helper processes that interact with Safari’s memory.

Background extensions are sneaky. Many apps install system extensions that run even after you quit the main app. Turn off any background extension you do not recognize.

After cleaning up, restart your Mac. A clean boot with fewer login items often shows immediate memory improvements when Safari opens.

You can also use Activity Monitor to spot background apps. Sort by Memory and look for processes you do not recognize. Search the process name online before quitting it to make sure it is safe.

Less is more on Apple Silicon. The M5 chip is efficient, but every background process steals a slice of unified memory that Safari could be using.

Reset Safari to Factory Settings

If nothing else works, a full Safari reset is your nuclear option. It removes all customizations, but it almost always cures stubborn memory leaks.

Apple no longer includes a single Reset Safari button, so you reset manually. Quit Safari. Open Finder, press Command + Shift + G, and go to ~/Library/Safari/.

Move the entire Safari folder to your desktop as a backup. Then go to ~/Library/Containers/com.apple.Safari/ and move that folder to the desktop too.

Now relaunch Safari. It will start completely fresh, as if you just bought your Mac. Every cache, cookie, extension setting, and tab will be gone. Sign back into iCloud to restore your bookmarks and passwords.

Browse normally for a day and watch Activity Monitor. Memory use should stay reasonable. If the leak returns, the cause is an extension, a website, or macOS itself rather than Safari’s stored data.

Once you confirm Safari runs cleanly, delete the backup folders from your desktop. Do not restore them, because doing so brings the leak back.

This reset takes ten minutes but solves problems that hours of tinkering cannot. Save it for last, but do not be afraid to use it.

Restart Your Mac Regularly

Apple Silicon Macs are designed to stay on for weeks. But Safari memory leaks accumulate during long uptimes, especially if you use sleep instead of shutdown.

Make a habit of restarting your Mac M5 at least once every three days. A full restart clears all memory, kills zombie processes, and lets macOS rebuild caches from scratch.

To restart, click the Apple menu and choose Restart. Uncheck Reopen windows when logging back in before confirming. This prevents Safari from reloading every leaky tab the moment you log in.

Shutdown is even better than restart for clearing deep memory issues. Once a week, fully shut down your Mac and leave it off for at least one minute before powering back on.

You can also use Terminal to flush memory without restarting. Run sudo purge and enter your password. This forces macOS to clear inactive memory immediately. It is not a permanent fix, but it buys time during heavy work sessions.

Avoid the temptation to leave 50 tabs open across days. Treat Safari like a workspace. Close it when you are done, just like you would close a document. Your M5 will thank you with smoother performance and longer battery life.

Frequently Asked Questions

Why does Safari use so much RAM on my Mac M5?

Safari uses RAM aggressively because Apple Silicon Macs have fast unified memory. The browser caches pages, preloads links, and keeps tabs warm for instant switching. This is normal up to a point, but extensions, old caches, and buggy websites can push memory use far beyond healthy levels.

Is a Safari memory leak dangerous for my Mac?

No, it will not damage your hardware. But it does cause slowdowns, app crashes, and excessive SSD writes from swap. Long term swap activity can shorten your SSD’s lifespan, so fixing leaks protects your Mac in the long run.

How much memory should Safari normally use on M5?

With 5 to 10 tabs open and no heavy web apps, Safari should use between 1GB and 3GB total across all its processes. Heavy users with 30 plus tabs may see 5GB to 8GB, which is still normal. Anything above 15GB usually means a leak.

Should I switch to Chrome or Firefox instead?

Not necessarily. Chrome uses more memory per tab than Safari on Apple Silicon. Firefox is lighter but lacks deep Mac integration. If Safari leaks persist after all fixes, try a different browser temporarily, but Safari is usually the most efficient choice for M5.

Will resetting Safari delete my passwords and bookmarks?

No, if you use iCloud Keychain and iCloud Bookmarks, your passwords and bookmarks live in iCloud, not in Safari’s local files. Resetting Safari only clears local caches, extensions, and settings. Your synced data returns the moment you sign back in.

How often should I clear Safari cache on my M5?

Once every two to three months is plenty for most users. If you browse heavily or notice slowdowns sooner, clear it monthly. Daily clearing is unnecessary and forces Safari to rebuild caches, which actually slows browsing temporarily.