# How to install an extension in Safari on Mac: App Store steps, settings, and fixes

> Learn how to install an extension in Safari on Mac: update macOS, get it from the App Store, turn it on in Settings, and fix common problems.

URL: https://www.lazur.app/how-to/install-an-extension-in-safari
Updated: 2026-11-08

To install an extension in Safari on Mac, choose Safari > Safari Extensions, click Get, then Install. First update macOS, since Safari 12 or later is required, then check the box under Safari > Settings > Extensions.

## Quick answer

- Update macOS first. Apple says Safari 12 or later is required to get extensions from the App Store.
- Choose Safari > Safari Extensions, click Get, click Install, then click Open to finish setup.
- Turn extensions on or off with the checkbox in Safari > Settings > Extensions.
- Set which websites an extension can use with Edit Websites. On macOS Sonoma 14 or later, allow it for Private windows separately.
- Old .safariextz files do not load. Look for the App Store version instead.

Applies to: Safari 12 or later on macOS, using extensions from the App Store. Time: 10 min. Difficulty: Easy.

## What you need

- macOS updated to the latest version your Mac supports
- Safari 12 or later to get extensions from the App Store
- An Apple Account, if Apple asks you to sign in during the install
- macOS Sonoma 14 or later, for the Private window access rules
- macOS Ventura 13 or later, plus iCloud for Safari and two-factor authentication, to share across devices
- macOS 27 and Apple Intelligence, only for Describe an Extension

## How to Install a Safari extension on a Mac in Safari on a Mac

1. **Update macOS first.** (Apple menu > System Settings > General > Software Update) Update macOS before anything else. Apple's Safari extensions page says to do this first, and that page is dated September 14, 2026. An updated Mac also gives you a current Safari, because Safari ships with macOS updates. Tip: Keep the Mac plugged in during a large update.
2. **Open Safari.** (Dock > Safari) Click Safari in the Dock, or open it from the Applications folder. Stay in Safari for the next steps, because the extension menu lives in Safari's menu bar.
3. **Open the Safari Extensions page.** (Safari > Safari Extensions) With Safari in front, click Safari in the menu bar, then choose Safari Extensions. The App Store opens to the Safari Extensions page. Tip: If the App Store does not open, check your macOS and Safari versions first.
4. **Pick an extension.** Search the App Store by name if you already know it. Otherwise, browse the Safari category. Each listing shows a Get button, or a price for a paid extension. Tip: Read the description before you click anything.
5. **Click Get, then Install.** Click Get, or the price for a paid extension. Then click Install. If Apple asks you to sign in, use your Apple Account.
6. **Click Open and finish setup.** After installation, click Open. Follow the onscreen instructions the extension shows. Each extension has its own setup, so read each screen before you click the next button.
7. **Turn the extension on in Settings.** (Safari > Settings > Extensions) Choose Safari > Settings. Click Extensions, then tick the checkbox beside the extension's name. Older releases call the settings window Preferences. Tip: If you use another profile, open its Extensions tab under the Profiles tab and turn the extension on there.
8. **Choose which websites it can use.** Select the extension in the Extensions list and click Edit Websites. Add each site you want the extension to work on, and set its access for that site. Tip: Leave the list alone if the extension works everywhere you need it.
9. **Allow it in Private windows if you need it.** (Safari > Settings > Extensions) On macOS Sonoma 14 or later, extensions that need website access are off in Private windows by default. Select the extension in the sidebar and choose Allow in Private Browsing.

Safari comes built into every Mac, so it is probably the first browser you open. StatCounter put Safari at 7.83% of worldwide desktop browser use in October 2026, while Chrome had 66.98%. Those figures cover every desktop system, so they show the whole market, not just Macs. Other trackers report different numbers, so treat them as a rough guide.

This guide walks through the official route. You install extensions from the App Store, turn them on in Safari's settings, decide which websites they can use, and remove them when you are done. It also covers common problems and what to try first.

![Person at a laptop browsing the web, the everyday setting for how to install an extension in Safari on Mac](https://images.lazur.app/content-images/howto/install-an-extension-in-safari/how-to-install-an-extension-in-safari-1-d0b7de.jpg)

## What you need before you install

Start with macOS. Apple's support page says to update macOS first, and that page is dated September 14, 2026. Extensions from the App Store need Safari 12 or later. Safari ships with macOS updates, so an updated Mac gets a current Safari too. For example, Safari 26 ships with macOS Sequoia 15 or later updates.

- Your macOS version. Choose Apple menu > About This Mac to see it.
- Your Safari version. Choose Safari > About Safari to see it.
- Whether you can sign in with an Apple Account. Apple may ask for one during the install.
- The kind of file you have. A download ending in .safariextz will not load.

Apple may ask you to sign in with your Apple Account during the install. If you cannot sign in, the install cannot finish. Keep your password and your two-factor code ready before you start.

## Install the extension from the App Store

The menu item does not install anything by itself. Choosing Safari > Safari Extensions opens the App Store on the Safari Extensions page. The install happens there, when you click Get and then Install. Safari adds the extension after that step.

Use the App Store search box if you already know the name. Otherwise, browse the Safari category, which Apple describes as the place to find and add extensions. Each listing shows a Get button, or a price for paid extensions.

Some extensions cost money. If the developer name looks unfamiliar, read the description twice before you buy or install. A short description with vague claims is a reason to skip the listing and look for another one.

## Turn an extension on or off in Safari Settings

After install, the extension lives in Safari's settings. Choose Safari > Settings, then click Extensions. Older releases call the window Preferences. Tick the checkbox beside the extension to turn it on. Untick it to turn it off without deleting it.

Safari can leave some extensions off for you. Apple says extensions that slow browsing are turned off when you first open Safari, until you turn them on. If an extension seems to do nothing, check that box before you try anything else.

| Task | Where to go | What you see |
| --- | --- | --- |
| Install an extension | Safari > Safari Extensions | The App Store opens to the Safari Extensions page |
| Turn on or off | Safari > Settings > Extensions | A checkbox beside each extension |
| Set website access | Select the extension, then Edit Websites | A list of sites with an access setting for each |
| Allow in Private windows | Select the extension in the sidebar (Sonoma 14 or later) | An Allow in Private Browsing choice |
| Uninstall | Safari > Settings > Extensions | Select the extension, then click Uninstall |
| Reload a page | View > Reload Page | Shortcut Command-R, shown as ⌘R |

_Where each extension control lives in Safari on Mac_

- **7.83%** Safari share of worldwide desktop browser use, October 2026 ([source](https://gs.statcounter.com/browser-market-share/desktop/worldwide))
- **Safari 12** Earliest Safari version Apple lists for getting extensions from the App Store ([source](https://support.apple.com/en-us/102343))
- **September 17, 2026** Release date of Safari 27.0, according to WebKit ([source](https://webkit.org/blog/18325/webkit-features-for-safari-27-0/))

## Set which websites an extension can use

Many extensions read or change web pages. Safari lets you decide where each one runs. Select the extension in Safari > Settings > Extensions, then click Edit Websites. Each website you add gets its own access setting.

Here is a worked example. Say you install an extension that changes how news sites look. Add the news sites you read, and leave the rest of the web out of its list. Changing that list does not remove the extension. It only changes where the extension works.

## Use extensions in Private windows

Private windows follow their own rule on newer Macs. On macOS Sonoma 14 or later, extensions that need website access are off by default in Private windows. Select the extension in the sidebar, then choose Allow in Private Browsing.

![Silver MacBook on a desk, the kind of Mac where you install an extension in Safari on Mac](https://images.lazur.app/content-images/howto/install-an-extension-in-safari/how-to-install-an-extension-in-safari-2-b2292d.jpg)

Profiles add another layer. Each Safari profile has its own Extensions tab, found in the Profiles tab. Extensions are off by default for new profiles, so you turn them on there for each profile you use.

## Uninstall an extension you no longer need

To remove an extension, choose Safari > Settings > Extensions, select the extension, and click Uninstall. Custom extensions you made with Describe an Extension show Delete instead.

Off and uninstalled are not the same. Turning an extension off keeps it on your Mac. Uninstalling removes it. Apple also says that uninstalling on one device does not remove it from other devices.

> **Old .safariextz files:** Old .safariextz extensions do not load and do not appear in Safari settings. You cannot turn them on, so look for a current App Store version instead.

## Share extensions with your other Macs

Safari can share an extension across your Macs. Open Safari > Settings > Extensions, then select Share across devices at the bottom. The sharing option has its own requirements, so check them before you rely on it.

You need macOS Ventura 13 or later on each Mac. You also need the same Apple Account, iCloud set up for Safari, and two-factor authentication. Without those, sharing will not work.

## Make your own extension with Describe an Extension

Apple added a way to build a small custom extension from plain words. Click the Page Menu button in the Smart Search field and choose Describe Extension. Enter what you want, click Next, then click Create.

You can then Try the extension, View it, Edit it, and Save it. This feature needs macOS 27 and Apple Intelligence. Apple says Apple Intelligence is not available in every language or region, and usage limits may apply.

Custom extensions cannot load remote content. They cannot use third-party services or access files on your Mac. Plan your idea around those limits before you start building.

![Person typing on a laptop while turning on a Safari extension in settings](https://images.lazur.app/content-images/howto/install-an-extension-in-safari/how-to-install-an-extension-in-safari-3-4c2f7b.jpg)

## Fix an extension that does not work

Start with the cheapest fix. Reload the page with View > Reload Page, or press ⌘R. Apple's troubleshooting page puts reloading first. Then work through the checks below, and change one thing at a time so you know what helped.

1. Reload the page with View > Reload Page or ⌘R.
2. Update macOS. Apple notes that Safari 26 ships with macOS Sequoia 15 or later updates.
3. Turn extensions off one at a time in Safari > Settings > Extensions, and reload the page after each change.
4. Update the extension itself from the App Store.
5. Under Websites settings, check whether a content blocker needs to be turned off.

If the problem stays, report it. After reloading, click the Page Menu button in the Smart Search field and choose Report a Website Issue. Describe the problem, then click Report. This option appears in Safari 26 or later.

> **Change one thing at a time:** If you turn every extension off at once, you cannot tell which one caused the problem. Turn off one, reload, and test before you move on.

## Common mistakes to avoid

- Expecting the Safari Extensions menu item to install the extension by itself. You still click Get and Install in the App Store.
- Stopping at Install. Click Open, follow the onscreen setup, then check the box in Settings.
- Downloading an old .safariextz file. Safari does not load it.
- Forgetting Private windows on macOS Sonoma 14 or later. The extension stays off there until you allow it.
- Skipping Edit Websites, then wondering why an extension does nothing on one site.
- Assuming an install on one Mac covers every Mac. Each Mac needs its own install, or you use Share across devices.

## Older Safari and macOS versions

Menu names change between releases. Apple's current pages say Settings. Older Safari releases say Preferences, so the path becomes Safari > Preferences > Extensions. Read the menu on your own screen before you follow a path.

WebKit says Safari 27.0 was released on September 17, 2026. Its web extension notes add reporting for uncaught JavaScript exceptions and unhandled promise rejections. These changes mostly matter to people who write extensions, not to people who install them.

## What to do after the install

Install one extension, turn it on, and test it on a site you visit every day. Once it behaves, add the next one. Keep the list short, so you know which extension to check when a page misbehaves.

Open Settings > Extensions again every so often. Remove anything you no longer use, and check the website access for anything new before you rely on it.

## Shortcuts

- Reload Page in Safari: ⌘R

## If it does not work

- **The extension does nothing on a page** Reload the page with View > Reload Page or ⌘R, then check the checkbox under Safari > Settings > Extensions and the Edit Websites list.
- **You cannot tell which extension causes a problem** Turn extensions off one at a time in Settings > Extensions, and reload the page after each change.
- **The extension seems out of date** Update the extension from the App Store, then reload the page.
- **A content blocker stops the extension** Under Websites settings, check whether a content blocker needs to be turned off.
- **The extension is missing in Private windows** On macOS Sonoma 14 or later, select the extension in the sidebar and choose Allow in Private Browsing.
- **A website still misbehaves after every fix** In Safari 26 or later, click the Page Menu button in the Smart Search field and choose Report a Website Issue.

## With Lazur

Lazur is a voice assistant for the Mac that lives in the notch. Hold ⌥ ⌘ and ask; it sees your screen, answers out loud, points at buttons and walks you through apps. Hold fn to dictate. Free for 3 days, then $18/month: https://www.lazur.app/download

- “Walk me through installing an extension in Safari.”: Lazur circles Safari Extensions in the menu bar, then waits while you click it before it names the next step. (Walks you through it)

## FAQ

### Why does Safari > Safari Extensions open the App Store?

Safari extensions are installed from the App Store. Apple sends you there because the Safari Extensions page lists them. Click Get, then Install, and the extension is added to Safari.

### Do I need an Apple Account to install a Safari extension?

Apple says you may be asked to sign in with your Apple Account during the install. If Apple asks and you cannot sign in, the install cannot finish. Check your sign-in details before you start.

### Which Safari version do I need?

Apple says Safari 12 or later is required to get extensions from the App Store. Update macOS first, since Apple's steps begin there, and then check your version under Safari > About Safari.

### Why is my extension off after I installed it?

Safari turns off extensions that slow browsing when you first open Safari. Go to Safari > Settings > Extensions and tick the checkbox. If you use another profile, check its Extensions tab too.

### Why does my extension not work in Private windows?

On macOS Sonoma 14 or later, extensions that need website access are off by default in Private windows. Select the extension in the sidebar and choose Allow in Private Browsing.

### Does uninstalling on one Mac remove the extension from my other Macs?

No. Apple says uninstalling on one device does not remove the extension from other devices. Uninstall it on each Mac where you want it gone.

### Can Safari open an old .safariextz extension?

No. Safari does not load legacy .safariextz extensions. They do not appear in Safari settings, and you cannot turn them on. Look for a current version in the App Store.

### What is Describe an Extension?

It is a feature that builds a small custom extension from a plain description. It needs macOS 27 and Apple Intelligence, and custom extensions cannot load remote content or access files on your Mac.

## Sources

1. [Apple Support: Use Safari extensions on your Mac](https://support.apple.com/en-us/102343), Apple, checked 2026-11-08
2. [Use Safari extensions on your Mac (HT202447)](https://support.apple.com/en-us/HT202447), Apple, checked 2026-11-08
3. [Apple Support Guide: Get extensions to customize Safari on Mac](https://support.apple.com/guide/safari/get-extensions-sfri32508/mac), Apple, checked 2026-11-08
4. [Apple Support: If Safari doesn't work as expected on Mac](https://support.apple.com/en-us/102564), Apple, checked 2026-11-08
5. [WebKit Features for Safari 27.0](https://webkit.org/blog/18325/webkit-features-for-safari-27-0/), WebKit, checked 2026-11-08
6. [StatCounter: Desktop Browser Market Share Worldwide](https://gs.statcounter.com/browser-market-share/desktop/worldwide), StatCounter, checked 2026-11-08
7. [Safari - Apple](https://www.apple.com/safari/), Apple, checked 2026-11-08