# Proton VPN extension for Firefox: installation, coverage and limits URL: https://webvpn.org/vpn/category/firefox Updated: 2026-08-31 How the Proton VPN extension for Firefox works, how to install it and check for WebRTC leaks, how it compares with Mozilla VPN, and what it does not protect. ## Where Firefox stands The Proton VPN extension for Firefox does the same job as its Chrome counterpart: it routes Firefox's traffic through Proton's servers so that websites see the server's address, and it leaves every other app on the device alone. According to protonvpn.com, the extension is a feature of paid plans, while the free plan is available in the desktop and mobile apps that cover Firefox along with everything else. Firefox adds two things Chrome does not. Mozilla sells its own system-wide VPN, and Firefox exposes a setting that fully disables WebRTC, the browser feature most often responsible for leaking a real address around an extension. ## Installing the Proton VPN Firefox add-on - Follow the Firefox Add-ons link from protonvpn.com. Search results on the add-ons site include unrelated extensions with similar names, so start from Proton's page. - Click Add to Firefox and accept the permission request, which will include access to proxy settings. - Click the toolbar icon and sign in with a Proton account on a plan that includes the extension. - Choose a location and connect. - In the extension settings, turn on WebRTC leak protection if it is not already on. - Load a what is my IP page in Firefox. The address and location should belong to the server. Reload the same page in a different browser to confirm the real address is still shown there, which is expected behaviour for an extension. ## WebRTC and other Firefox leak checks WebRTC lets sites set up direct connections for calls and file sharing, and in the process it can reveal your local and public addresses even when a proxy or extension is active. Firefox lets you handle this two ways: - Extension toggle. Most VPN extensions block the WebRTC address disclosure while keeping calls working. This is the default choice. - about:config. Set media.peerconnection.enabled to false to disable WebRTC entirely. Video calls in the browser stop working until you turn it back on. After either change, run a WebRTC leak test page and confirm only the VPN server's address appears. Also check DNS: Firefox can use its own encrypted DNS resolver under Settings, Privacy and Security, DNS over HTTPS, which hides lookups from the local network even without a VPN. ## Mozilla VPN and the full app Mozilla VPN is a separate product from Mozilla, available at mozilla.org, that runs as a system-wide app on desktop and mobile and uses Mullvad's server network under a published privacy policy. It covers all apps rather than only Firefox and has no free tier. It is one of several full apps that meet the no-logs checklist, alongside Proton VPN's and Mullvad's own apps. The choice between extension and app is the same as on Chrome. An extension gives Firefox a different location from the rest of your device; an app covers everything and includes a system-level kill switch. Running an app as the default and adding the extension for a second location in Firefox is a common combination. ## Firefox's own privacy features Firefox includes Enhanced Tracking Protection, which blocks known trackers and some fingerprinting scripts, and Total Cookie Protection, which isolates cookies per site. These reduce how well sites can recognise you across the web, which complements an address change. None of them alters your address, so they are not a substitute for an extension, a VPN or Tor Browser. Tor Browser is itself built on Firefox. If your goal is anonymity for a browser rather than a change of apparent country, Tor Browser from torproject.org delivers that with the same interface you already know. The browser guide compares the options. ## What the extension does not protect Traffic outside Firefox, signed-in accounts, cookies already set, and fingerprinting all remain unchanged. A disabled or crashed extension silently reverts Firefox to your real address, because there is no system kill switch behind it. And the extension does nothing against malicious downloads or phishing pages; those are handled by Firefox's own protections. ## Recommended setup Install the extension from Proton's link if you have a plan that includes it, or install the desktop app if you want the free tier. Enable WebRTC protection, turn on DNS over HTTPS in Firefox, and verify the address and leak test pages once. For an explanation of the trade-offs involved in trusting any provider, read are VPNs safe. For the full set of methods beyond the browser, see how to hide your IP address. ## FAQ Q: Does Proton VPN have a Firefox extension? A: Yes. Proton publishes a Firefox add-on, listed on protonvpn.com with a link to the Firefox Add-ons site. It routes Firefox traffic through Proton's servers and requires a paid Proton VPN plan; the free plan works in the desktop and mobile apps instead. Q: Is Mozilla VPN the same as a Firefox extension? A: No. Mozilla VPN is a paid, system-wide VPN app for Windows, macOS, Linux, Android and iOS that uses Mullvad's server network. It covers every app, not only Firefox. Details are on mozilla.org. Q: How do I stop Firefox leaking my real address through WebRTC? A: Most VPN extensions include a WebRTC protection toggle. You can also open about:config and set media.peerconnection.enabled to false, which disables WebRTC entirely and breaks browser-based video calls. The extension toggle is the less disruptive option. Q: Does Firefox private browsing hide my address? A: No. Private windows discard history and cookies when closed. Your address is unchanged. Only an extension, a system VPN or Tor Browser changes what sites see. Q: Can I use the extension on Firefox for Android? A: Firefox for Android supports a limited set of extensions. Check the Firefox Add-ons site for current compatibility. On Android the provider's app covers Firefox and every other app, which is usually the simpler route.