When Safari starts crawling, spinning on a blank page, or flat-out refusing to load sites that work fine on your phone, it is almost never a broken Mac. It is usually one bad extension, a corrupt cache, a stale DNS entry, or an experimental setting Apple left on. Work these in order, top to bottom — the first few fix the vast majority of cases in under two minutes.
First: is it Safari, or the whole Mac?
Two quick checks tell you where the problem lives:
- Open the same page in another browser (Chrome, Firefox, or even a private Safari window). If it loads instantly there, the problem is Safari, and this guide is for you.
- Check another device on the same Wi-Fi. If pages are slow on your phone too, the issue is your network or ISP, not your Mac — restart your router before anything else.
If the Mac itself feels slow everywhere — beachballing in Finder, apps taking forever to open — this is the wrong guide. Start with MacBook running slow? Every fix in order instead.
The fixes, fastest first
1. Force-reload and try a private window
Hold Shift and click the reload button (or press Command-Shift-R) to bypass the cached copy of the page. Still stuck? Open a private window (Command-Shift-N) and load the same site. A private window ignores your extensions, cookies, and most cached data — if the page loads fine there, you have just narrowed it to website data or an extension (fixes 2 and 3). See how to use private browsing in Safari.
2. Clear this site’s data (not everything)
A single site with a corrupt cache or a broken cookie can hang forever. You do not need to nuke everything — clear just the offending site:
- Safari menu → Settings → Privacy → Manage Website Data.
- Type the site’s name in the search box, select it, and click Remove.
- Reload the page.
If several sites misbehave, clear the whole Safari cache instead — the safe, step-by-step way is in how to clear the cache on a Mac.
3. Disable extensions — the number-one cause
A single outdated ad blocker, VPN, or content blocker is behind more Safari slowdowns than anything else. Turn them all off at once, then add back one at a time:
- Safari menu → Settings → Extensions.
- Uncheck every extension in the list.
- Reload your slow page. Fast now? Re-enable extensions one by one, reloading after each, until the culprit reveals itself — then delete or update it.
Full walkthrough: how to use Safari extensions on a Mac.
4. Flush the DNS cache
If pages hang on “Looking up…” or you get “Safari can’t find the server” on sites you know are up, your Mac is holding a stale DNS record. Flush it:
- Open Terminal (Applications → Utilities).
- Run:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder - Enter your password (nothing shows as you type — that is normal) and press Return.
Still resolving slowly? Switch to a faster public DNS in System Settings → Network → your connection → Details → DNS and add 1.1.1.1 and 8.8.8.8. More detail on DNS flushing lives in the clear-the-cache guide.
5. Turn off experimental features
Safari has a hidden Develop menu full of experimental WebKit toggles. A single one left on can break page rendering or loading. Reset them:
- Safari menu → Settings → Advanced → check Show features for web developers.
- A Develop menu appears in the menu bar → open it → Feature Flags (or Experimental Features on older macOS).
- Scroll to the bottom and click Reset All to Defaults. Quit and reopen Safari.
6. Check your date, time, and content blockers
A wrong system clock silently breaks HTTPS, so secure pages refuse to load. Set System Settings → General → Date & Time to update automatically. Also confirm no Screen Time or parental-control content filter is quietly blocking the site (System Settings → Screen Time → Content & Privacy).
7. Update macOS and restart
Safari ships with macOS, so a stuck version can carry loading bugs that an update fixes. Go to System Settings → General → Software Update, install anything pending, and restart. A restart alone clears memory pressure that can make every browser feel sluggish.
The honest part: when it is the Mac, not Safari
If Safari is still slow after every fix — and other browsers drag too, and the fan is loud, and everything beachballs — the browser is not the problem. On older Macs, an aging drive, too little RAM, or a swollen battery throttling the CPU will make the whole machine (Safari included) crawl. At that point you are maintaining hardware past its useful life.
If yours is at that stage, it may be worth more toward a newer Mac than you think. See what a working (or even broken) Mac is worth as a trade-in, or browse the Apple clearance deals on faster, checked machines that will not leave you staring at a spinner.
Frequently Asked Questions
Why is Safari so slow but Chrome is fast on my Mac?
Almost always a Safari-only cause: a bad Safari extension, corrupt website data for one site, or a stuck experimental feature flag. Disable all Safari extensions, clear the site’s website data, and reset feature flags (fixes 2, 3, and 5 above) — those resolve the large majority of “Safari slow, Chrome fine” cases.
Why do pages spin and never load in Safari?
A page that spins forever is usually waiting on DNS or a blocked resource. Flush the DNS cache (fix 4), try a private window to rule out extensions, and check that your system clock is correct so HTTPS does not silently fail.
Does clearing the cache speed up Safari?
It helps when a specific site is misbehaving or after a Safari update, but it is not a routine speed-up. Clearing website data for the one broken site is safer than wiping everything. The full detail on what cache clearing does and does not do is in how to clear the cache on a Mac.
Will resetting Safari delete my bookmarks or passwords?
No. Clearing website data, disabling extensions, and resetting feature flags do not touch your bookmarks, saved passwords, or reading list. Only removing an extension deletes that extension’s own settings.
How do I know if it is my internet and not Safari?
Load the same site on your phone over the same Wi-Fi, or in another browser on the Mac. If it is slow everywhere, restart your router and contact your ISP — the Mac is fine. If only Safari struggles, work the fixes above.