Download Firefox directly from Mozilla's website
Go to mozilla.org in your web browser and click the large download button on the homepage. Firefox will detect your operating system — Windows, Mac, or Linux — and offer you the correct version automatically. You do not need to choose between versions yourself.
The download starts immediately. Depending on your internet speed, the file (around 50 megabytes) takes between 30 seconds and a few minutes to arrive. Your browser will show a progress bar or notification when it finishes. Do not close your browser while the download is happening.
If you are using a work computer or school computer, Firefox may already be blocked by your network administrator. If the download does not start, contact your IT department — they control what software can be installed on that machine.
Key Takeaways
- Download Firefox from mozilla.org, not from a search result or email link, to avoid fake versions.
- Firefox automatically detects whether you need the Windows, Mac, or Linux version and downloads the right one.
- After download completes, you must run the installer file and follow the on-screen steps to finish setup.
- Firefox is free and does not require a password, credit card, or Mozilla account to install and use.
Run the installer and complete setup on Windows
Once the download finishes, look for a file named something like "FirefoxInstaller.exe" in your Downloads folder. Double-click it to start the installer. A window will open asking where you want Firefox to live on your computer — the default location works for almost everyone, so click "Install" and wait.
The installer copies Firefox files to your computer, which takes one to two minutes. When it finishes, a new window appears asking whether you want Firefox to be your default browser. You can choose yes or no — this does not affect whether Firefox works. Click "Finish" to close the installer.
Firefox is now installed. You will see a Firefox icon on your desktop or in your Start menu. Click it to open Firefox for the first time. The browser will ask whether you want to import bookmarks and passwords from your old browser — you can do this now or skip it and set up Firefox later.
Install Firefox on Mac
After the download finishes, look in your Downloads folder for a file called "Firefox.dmg". Double-click it to open it. A window appears showing the Firefox icon and an Applications folder icon with an arrow between them.
Drag the Firefox icon into the Applications folder. This copies Firefox to the place where Mac stores programs. When the copy finishes, you can close this window and eject the Firefox.dmg file by dragging it to the Trash.
Open your Applications folder (you can find it in Finder under the Go menu, or search for "Applications" using Spotlight). Look for Firefox and double-click it to launch the browser. The first time you open it, Mac will ask you to confirm that you want to run software from the internet — click "Open" to proceed.
What to do if the download fails or seems stuck
If the download stops before reaching 100 percent, your internet connection may have dropped. Close your browser and try downloading again. If it keeps stopping at the same point, try a different web browser temporarily — this tells you whether the problem is with Firefox or with your internet connection.
If you see a message saying the file is "corrupted" or "damaged" after download, delete the file and download again. Corruption happens occasionally when data transfers over the internet and can usually be fixed by starting over.
If the download button on mozilla.org does not respond when you click it, clear your browser's cache and cookies, then try again. Instructions for clearing cache vary by browser, but you can usually find the option under Settings or Preferences in the menu.
Avoid fake Firefox downloads
Firefox is free, and Mozilla never asks for payment, a credit card, or personal information to download it. If a website claims to offer Firefox but asks for money or your email address before downloading, that is not the real Firefox.
Always download from mozilla.org directly. Do not click Firefox download links in search results, emails, or pop-up ads — these often lead to fake versions that contain unwanted software. When in doubt, type mozilla.org into your address bar yourself rather than clicking a link.
If you have already downloaded a file from somewhere else and are not sure whether it is real, delete it and download again from mozilla.org. It takes only a few minutes and is safer than guessing.
Set up Firefox after installation
When Firefox opens for the first time, you will see a welcome screen. You can import bookmarks and passwords from your old browser, or skip this step and add them later. Firefox will also ask whether you want to set it as your default browser — you can change this decision anytime in Firefox settings.
Create a Firefox account if you want to sync bookmarks, passwords, and open tabs across multiple computers. This is optional — Firefox works perfectly without an account. If you do create one, use a password you do not use anywhere else.
Spend a moment looking at the toolbar at the top of the window. The address bar (where you type website names) is in the center. The menu button (three horizontal lines) on the right side opens settings, bookmarks, and other options. You can customize the toolbar by right-clicking it and selecting "Customize Toolbar".
Frequently Asked Questions
Do I need to uninstall my old browser before installing Firefox?
No. You can have multiple browsers on the same computer at the same time. Firefox will not interfere with Chrome, Edge, Safari, or any other browser you already have. You can keep your old browser and use Firefox alongside it, or uninstall the old one later if you prefer.
Can I install Firefox on a tablet or phone?
Yes. Firefox is available for iPhone, iPad, and Android devices through the App Store or Google Play. Search for "Firefox" in your device's app store and tap the download button. The process is the same as installing any other app on your device.
What if I get an error message during installation?
The most common error is "You do not have permission to install software." This means your computer is set up so that only an administrator can install programs. Ask the person who manages your computer (or contact IT if it is a work machine) to install Firefox for you, or give you administrator access temporarily.
Is Firefox safe to download and use?
Yes. Firefox is made by Mozilla, a nonprofit organization, and is one of the most widely used browsers in the world. It is free from viruses and malware when downloaded from mozilla.org. Like all browsers, Firefox receives security updates regularly, which it installs automatically.
Can I use Firefox without creating an account?
Yes, completely. Firefox works without any account. Creating a Firefox account is optional and only needed if you want to sync your bookmarks and passwords across multiple computers. You can start using Firefox immediately after installation without signing up for anything.