How to Use Firefox Portable on a USB Drive (2026)

Want your browser, bookmarks, passwords and extensions on a USB stick so you can use them on any Windows PC? That’s what Firefox Portable does. We first wrote about Portable Firefox in 2005, when it was a 17 MB download from an enthusiast project. Today it’s maintained by PortableApps.com, updated with every Firefox release, and still free. Here’s how to set it up in 2026.

Quick answer: Download Mozilla Firefox, Portable Edition from PortableApps.com, run the installer and choose your USB drive as the location. Launch FirefoxPortable.exe from the drive on any Windows PC; your bookmarks, settings, extensions and saved passwords stay on the USB stick and nothing is installed on the computer. Use a primary password to protect saved logins.

How to install Firefox Portable on a USB drive

1. Go to Firefox Portable on PortableApps.com and download the installer.
2. Plug in your USB drive (8 GB or more and USB 3.0 is best for speed).
3. Run the installer and choose the USB drive as the destination.
4. Open the drive and launch FirefoxPortable.exe.
5. Sign in to Firefox Sync if you want your bookmarks and passwords from other devices.

Why use Firefox Portable?

• Your browser anywhere: same bookmarks, extensions and settings on library, school or office PCs.
• No installation needed: useful when you don’t have admin rights.
• Leaves fewer traces: your profile stays on the USB drive rather than the PC.
• Testing: developers can run separate Firefox versions side by side.

Security tips

• Set a primary password in Firefox settings so nobody can read saved passwords if you lose the drive.
• Use private windows on shared computers for extra protection.
• Remember the PC can still see what you type: a portable browser doesn’t protect you from keyloggers on an untrusted computer.
• Eject safely before unplugging to avoid corrupting your profile.
• Consider an encrypted USB drive for sensitive data.

Keeping it updated

Firefox Portable updates itself like regular Firefox, or you can use the PortableApps.com Platform to update all your portable apps at once. Keeping it updated is important for security.

Alternatives

• Firefox Sync or Chrome sync: if you can install or sign in to a browser, sync gives you your data without a USB drive.
• Google Chrome Portable and other browsers are also available on PortableApps.com.
• Mac and Linux: Firefox Portable is for Windows; use sync instead on other systems.

Build a complete toolkit with our best portable apps for a USB drive, and format your USB drive correctly first.

FAQ

Is Firefox Portable official?

It’s packaged by PortableApps.com using official Mozilla Firefox code, with a launcher that keeps everything on the drive.

Does Firefox Portable work on Mac?

No. It’s for Windows; Mac users can use Firefox with Sync instead.

Does Firefox Portable leave traces on the PC?

It keeps your profile on the USB drive, but Windows may still log some activity, so use private windows on shared PCs.