Mozilla Firefox is Mozilla’s free and open-source browser. The current Release version changes over time, so always check Mozilla’s official download page for the latest version. Official: firefox.com / mozilla.org. Firefox is available as an online installer, full/offline installers, MSI packages for IT deployment, and through the Microsoft Store on supported Windows versions. There is no “Firefox Premium unlocked.” If your Windows version is not supported by the current Release, check Mozilla’s Firefox ESR support options instead. This is not Chrome. Import bookmarks from another browser if you want. Don’t install a “Firefox + crack pack” from a download blog.

Download Firefox for Windows

Official download from Mozilla.
Get Firefox for your language and Windows architecture. Run the installer. After installation, open Help → About Firefox to check the installed version.

Download Firefox for Windows

Supported Windows versions · Current Release · Free · Download size varies by build and version

Main: firefox.com.
All languages / OS: Download in another language.
Install help: How to install Firefox on Windows.
Release information: Firefox release notes.
Do not run a file such as Firefox_Setup_Full_Crack.exe. That is not an official Mozilla build.

Work PCs: MSI / ESR / policy options are available from Mozilla for enterprise deployment. Don’t sideload a modified firefox.exe.

Install the current Release · Need ESR for an older Windows version? · Already have Firefox?

If you searched for “Firefox full,” “portable cracked,” or “faster Firefox pack”

There is no paid Pro browser edition of Firefox from Mozilla.

• Open firefox.com
• Download Firefox or an appropriate ESR build if Mozilla recommends it for your system
• Run the Mozilla installer
• Help → About Firefox = check your installed version

A “pre-optimized” folder plus a patched xul.dll or other modified Firefox files is not an official Mozilla distribution and may contain malware. Fake “Firefox Pro” keys or unlock codes are not required for the official browser.

Your download should start on firefox.com / mozilla.org

If an EXE has a suspicious name such as Firefox_Secure_Setup.exe or comes from an unrelated download site, leave. Installer sizes vary by version, architecture, language, and installer type, so file size alone is not a reliable authenticity check.

What to do next

1. firefox.com → Download Firefox.
2. Or all languages and platforms for available Windows builds, including offline and MSI options where offered.
3. Run the installer as a normal user; Windows may ask for UAC permission.
4. Import from Edge/Chrome if you want.
5. Help → About Firefox = check for the current installed version and updates.

Typical folder: C:\Program Files\Mozilla Firefox on a standard 64-bit installation.
Firefox profiles are stored separately from the program files. Avoid copying a “ready profile” from an unknown forum or download site.

Store: Firefox is also available through the Microsoft Store on supported Windows versions. Store installations receive updates through the Microsoft Store and can use a separate Firefox profile from a Mozilla-installed copy.

Windows may warn you. Check the publisher.

• The official Firefox installer is published by Mozilla; the exact publisher display can vary by Windows signing/display details.
• SmartScreen or another Windows warning can appear for legitimate downloads. Verify that you downloaded Firefox from Mozilla before proceeding.
• Do not turn off Defender or other security software to “speed up Firefox.”
• Updates: hamburger menu → Help → About Firefox (or enterprise policy).

Pick the right Windows file

Not this download

• “Firefox Portable unlocked” from an unknown download site
• Android APK on a Windows download page
• Waterfox / LibreWolf or another third-party browser labelled as Mozilla Firefox

Trial and licence

Firefox is free and open source. Mozilla makes Firefox available under the Mozilla Public License and other applicable open-source licensing terms. No product key is required. A Mozilla account is optional and can be used for features such as Sync.

Will it run on this PC?

Firefox’s Windows requirements can change as support evolves. Check Mozilla’s current system requirements before installing, especially if you are using an older Windows version or older hardware. Current Firefox builds support modern Windows versions, while older Windows releases may require a supported ESR version or may no longer be supported. Mozilla also provides different Windows builds for supported 64-bit, 32-bit, and ARM64 systems where available.

Already installed? Help → About Firefox checks for updates and shows your installed version. You do not need to hunt for a second “full” copy just because a newer version has been released.

Install, first window, and defaults

First run

1. Open Firefox.
2. Import or skip.
3. Settings → General → Startup / Default Browser options if you want Firefox as your default.
4. Extensions only from addons.mozilla.org or another source you trust.
5. Don’t install a “codec pack for Firefox” unless you have a specific, trusted reason.

Uninstall: Settings → Apps. Firefox profiles can remain after uninstalling unless you explicitly remove them.

If it did not work

• “Unsupported OS” — check Mozilla’s current system requirements and whether ESR is available for your Windows version.
• Won’t update — check Firefox’s update settings, enterprise policy, or whether you installed it through the Microsoft Store.
• A very small or oddly named “FX_Unlocked” installer from an unknown site — leave.

Why people still install official Firefox

• Independent browser
• Regular stable releases and security updates
• Free and open source

It will not make a dangerous site safe by itself. Keep Firefox, Windows, extensions, and other software updated and use normal security precautions.

Questions before you trust the installer

Is this the official file?
Download from firefox.com, mozilla.org, or the official Microsoft Store listing. Avoid modified or repacked installers from unrelated download sites.

Is it free?
Yes. The official Firefox browser does not require a paid activation key.

Safe?
An official Mozilla installer is the right source. Search-ad “Firefox full,” “cracked,” or “Pro” files from third-party sites are the bigger risk.

After you have the file

Install the current Firefox Release from firefox.com. Confirm the installed version in Help → About Firefox. If your Windows version is older, check Mozilla’s current support information and use ESR only where Mozilla supports it.

Install: support.mozilla.org
All builds: download/all

Publisher: Mozilla. Firefox is a Mozilla trademark. If a third-party site wraps Firefox in a crack, unlocker, “Pro” key, or modified installer, do not install it.