Mac Os Base System Download



If you download and install apps from the internet or directly from a developer, macOS continues to protect your Mac. When you install Mac apps, plug-ins, and installer packages from outside the App Store, macOS checks the Developer ID signature to verify that the software is from an identified developer and that it has not been altered. The history of macOS, Apple's current Mac operating system originally named Mac OS X until 2012 and then OS X until 2016, began with the company's project to replace its 'classic' Mac OS. That system, up to and including its final release Mac OS 9, was a direct descendant of the operating system Apple had used in its Macintosh computers since.

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This article explains how to download and install Firefox on a Mac.

  • If you are updating from a previous version of Firefox, see Update Firefox to the latest release.
Note: This article only applies to Mac. For instructions to install Firefox on Windows, see How to download and install Firefox on Windows.For instructions to install Firefox on Linux, see Install Firefox on Linux.
Make sure your Mac meets the System Requirements for Firefox.

If you use an old version of OS X, see these articles for more information:

Download
Note:Firefox version 83 and higher support both Intel-based Macs (x86 architecture) and Apple devices with the new ARM-based CPU (Apple Silicon). Firefox 83 runs on new Apple Silicon devices by way of Apple's Rosetta 2 emulation software and thus performance speeds may suffer. Firefox 84 and higher versions will run natively (not under emulation).

To download and install Firefox:

  1. Visit the Firefox download page in any browser (for example, Safari). It will automatically detect the platform and language on your computer and recommend the best version of Firefox for you.
  2. Click .
    • Note: If you want to have a choice of the language for your Firefox installation, click the Download options and other languages link instead.
  3. Once the download has completed, the file (Firefox.dmg) may open by itself and pop open a Finder window containing the Firefox application. Drag the Firefox icon on top of the Applications folder in order to copy it there.
    Note: If you do not see this window, open the Firefox.dmg file that you downloaded.
  4. After dragging Firefox to the Applications folder, hold down the control key while clicking in the window and select Eject 'Firefox' from the menu.
Complete the steps above before running Firefox. Do not run Firefox directly from the Firefox.dmg file, as this can result in issues such as lost data and settings.

Tip: You can add Firefox to your dock for easy access. Just open your Applications folder and drag Firefox to the dock.

Firefox is now ready for use. Just click on its icon in the dock or Applications folder to start it.

When you first start up Firefox, you will be warned that you downloaded Firefox from the Internet. Because you download Firefox from the official site, click .

Upon installation, Firefox will not be your default browser, which you'll be notified about. That means that when you open a link in your mail application, an Internet shortcut, or HTML document, it will not open in Firefox. If you want Firefox to do those things, click . If you're just trying out Firefox or simply do not wish to set Firefox as your default browser, click .

The safest place to get apps for your Mac is the App Store. Apple reviews each app in the App Store before it’s accepted and signs it to ensure that it hasn’t been tampered with or altered. If there’s ever a problem with an app, Apple can quickly remove it from the store.

If you download and install apps from the internet or directly from a developer, macOS continues to protect your Mac. When you install Mac apps, plug-ins, and installer packages from outside the App Store, macOS checks the Developer ID signature to verify that the software is from an identified developer and that it has not been altered. By default, macOS Catalina and later also requires software to be notarized, so you can be confident that the software you run on your Mac doesn't contain known malware. Before opening downloaded software for the first time, macOS requests your approval to make sure you aren’t misled into running software you didn’t expect.


Running software that hasn’t been signed and notarized may expose your computer and personal information to malware that can harm your Mac or compromise your privacy.

Mac Os Base System Download

View the app security settings on your Mac

By default, the security and privacy preferences of your Mac are set to allow apps from the App Store and identified developers. For additional security, you can chose to allow only apps from the App Store.

In System Preferences, click Security & Privacy, then click General. Click the lock and enter your password to make changes. Select App Store under the header “Allow apps downloaded from.”

Open a developer-signed or notarized app

If your Mac is set to allow apps from the App Store and identified developers, the first time that you launch a new app, your Mac asks if you’re sure you want to open it.

An app that has been notarized by Apple indicates that Apple checked it for malicious software and none was detected:

Prior to macOS Catalina, opening an app that hasn't been notarized shows a yellow warning icon and asks if you're sure you want to open it:

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If you see a warning message and can’t install an app

If you have set your Mac to allow apps only from the App Store and you try to install an app from elsewhere, your Mac will say that the app can't be opened because it was not downloaded from the App Store.*

If your Mac is set to allow apps from the App Store and identified developers, and you try to install an app that isn’t signed by an identified developer and—in macOS Catalina and later—notarized by Apple, you also see a warning that the app cannot be opened.

If you see this warning, it means that the app was not notarized, and Apple could not scan the app for known malicious software.

You may want to look for an updated version of the app in the App Store or look for an alternative app.

If macOS detects a malicious app

If macOS detects that an app has malicious content, it will notify you when you try to open it and ask you to move it to the Trash.

How to open an app that hasn’t been notarized or is from an unidentified developer

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Running software that hasn’t been signed and notarized may expose your computer and personal information to malware that can harm your Mac or compromise your privacy. If you’re certain that an app you want to install is from a trustworthy source and hasn’t been tampered with, you can temporarily override your Mac security settings to open it.

In macOS Catalina and macOS Mojave, when an app fails to install because it hasn’t been notarized or is from an unidentified developer, it will appear in System Preferences > Security & Privacy, under the General tab. Click Open Anyway to confirm your intent to open or install the app.

The warning prompt reappears, and you can click Open.*

The app is now saved as an exception to your security settings, and you can open it in the future by double-clicking it, just as you can any authorized app.

Privacy protections

macOS has been designed to keep users and their data safe while respecting their privacy.

Gatekeeper performs online checks to verify if an app contains known malware and whether the developer’s signing certificate is revoked. We have never combined data from these checks with information about Apple users or their devices. We do not use data from these checks to learn what individual users are launching or running on their devices.

Notarization checks if the app contains known malware using an encrypted connection that is resilient to server failures.

These security checks have never included the user’s Apple ID or the identity of their device. To further protect privacy, we have stopped logging IP addresses associated with Developer ID certificate checks, and we will ensure that any collected IP addresses are removed from logs.

Mac Os X Base System Download

In addition, over the the next year we will introduce several changes to our security checks:

  • A new encrypted protocol for Developer ID certificate revocation checks
  • Strong protections against server failure
  • A new preference for users to opt out of these security protections

*If you're prompted to open Finder: control-click the app in Finder, choose Open from the menu, and then click Open in the dialog that appears. Enter your admin name and password to open the app.