The best VPN Extensions for Firefox: Add-on vs. Mozilla VPN

As a Firefox user, you’ve already chosen a browser that prioritizes privacy. Adding the VPN Extensions for Firefox feels like the natural next step – a simple, convenient button in your toolbar to take that protection to the next level.

But the world of Firefox add-ons presents a unique set of questions. Should you trust Mozilla’s own VPN? What’s the real difference between a lightweight add-on and a full application? I have navigated the Mozilla Add-ons store for years. I’ve tested dozens of these tools. It’s easy to choose an add-on that offers a false sense of security. The biggest mistake is failing to understand the trade-offs between a simple browser proxy and a true, system-wide VPN.

Don’t let confusion compromise your privacy. Let me be your trusted guide to finding the perfect privacy companion for your Firefox browser.

Firefox VPN in 30 seconds: Your best options

For maximum privacy that aligns with Firefox’s values, Mozilla VPN (a full app) is an excellent choice, powered by Mullvad’s trusted network. For the best browser add-on experience, ExpressVPN’s ‘remote control’ extension is top-tier. For a feature-rich free option, Windscribe is unbeatable.

1. Our top 5 VPN add-ons for Firefox in 2025

While Mozilla VPN is an excellent full-app solution, sometimes you just want the convenience of a lightweight browser add-on. After testing dozens of options from the official Mozilla Add-ons store, I’ve selected the top five third-party extensions. These are all from reputable companies and provide a safe, reliable experience for your Firefox browser.

1. ExpressVPN: Best for reliability & full app control.
2. NordVPN: Best for speed & bonus security features.
3. Private Internet Access (PIA): Best for advanced in-browser privacy settings.
4. Windscribe: Best feature-rich free option (with a 10GB data cap).
5. Proton VPN: Best for unlimited free data.

Here’s how they compare at a glance before we dive into the detailed, hands-on reviews.

Add-on	Works Standalone?	Best Feature	Free Plan
ExpressVPN	No (controls app)	Full VPN security & features	No (Premium only)
NordVPN	Yes	Threat Protection Lite (ad blocker)	No (Premium only)
PIA	Yes	Advanced in-browser privacy controls	No (Premium only)
Windscribe	Yes	R.O.B.E.R.T. ad blocker	Yes (10GB/month data cap)
Proton VPN	Yes	Unlimited data	Yes (3 country locations)

I personally installed each of these add-ons into my Firefox browser to test their usability, performance, and unique features. Here’s the hands-on breakdown of how they performed. Now, let’s explore why each of these add-ons earned its spot.

1.1. #1 – ExpressVPN

The ExpressVPN Firefox add-on stands out because it’s not just a proxy – it’s a secure remote control for the full desktop application. As I’ve mentioned, this is a brilliant design. It gives you the one-click convenience of a browser button while guaranteeing you’re protected by the full, military-grade encryption of their complete VPN service. It’s the most secure add-on you can get for Firefox.

• Free or Paid: Requires a premium ExpressVPN account.
• Works Standalone: No, requires the desktop app to be running.
• Key Features: Full app control, WebRTC blocking, location spoofing, HTTPS Everywhere.

Hands-on experience

The add-on’s interface is clean, minimal, and operates with zero fuss. Connecting and switching server locations from the Firefox toolbar is instant. What really sets it apart are the built-in privacy tools. It has dedicated toggles to block WebRTC leaks. This is a common browser vulnerability that can reveal your real IP. It also spoofs your HTML5 geolocation data. This ensures websites see your VPN location, not your physical one. It even automatically enables “HTTPS Everywhere” to force more secure connections.

Requirement

This is crucial to understand: You must have the ExpressVPN desktop app installed and running for the add-on to function. The add-on is the brain, but the app is the muscle.

1.2. #2 – NordVPN

NordVPN‘s Firefox add-on is a powerful, standalone tool that brings some of its best security features directly into the browser. It’s exceptionally fast and includes Threat Protection Lite, which actively blocks malicious ads, trackers, and websites before they can even load. This provides a tangible security boost to your everyday browsing.

• Free or Paid: Requires a premium NordVPN account.
• Works Standalone: Yes, it’s a standalone encrypted proxy.
• Key Features: Threat Protection Lite (ad/malware blocker), Split Tunneling, fast speeds.

Hands-on experience

The add-on is very intuitive, with a simple “Quick Connect” button and a searchable server list. My favorite feature here is the in-browser Split Tunneling. This allowed me to add specific websites to a bypass list. For instance, I could route my general browsing through a UK server. Meanwhile, I can tell the add-on to bypass the VPN for my local news website. This ensures I still get relevant local content. It’s a very practical feature.

Performance

As a standalone proxy, the add-on is very lightweight and fast. I had no issues streaming HD content directly in Firefox and noticed no browsing slowdowns. It reliably unblocked every streaming service I pointed it at.

1.3. #3 – Private Internet Access (PIA)

The PIA Firefox add-on is a toolkit for the privacy-conscious. It offers a suite of advanced features that go beyond a simple proxy. This allows you to aggressively combat various tracking methods used by modern websites. It aligns perfectly with the Firefox philosophy.

• Free or Paid: Requires a premium PIA account.
• Works Standalone: Yes, it’s a standalone encrypted proxy.
• Key Features: Granular privacy controls (block trackers, third-party cookies, fingerprinting).

Hands-on experience

The add-on’s settings panel is where it truly shines. It’s packed with toggle switches for privacy features. With a few clicks, I was able to block third-party cookies, stop websites from accessing my camera or microphone, and prevent tracking via UTM parameters. It’s like having several different privacy extensions rolled into one. For anyone who likes to fine-tune their digital footprint, this level of control is fantastic.

Performance

The connection is fast and stable. In fact, by blocking so many trackers and scripts, I found that many ad-heavy websites actually loaded faster with the PIA add-on enabled.

1.4. #4 – Windscribe

Windscribe consistently earns its place as the best free VPN add-on for Firefox. It’s a genuinely useful service from a reputable company. You get a generous 10GB of free data per month (if you confirm your email), which is far more than most “free” trials, plus access to their powerful ad and tracker blocker. It feels like a premium product, offered for free.

• Free or Paid: Offers a generous free plan and a premium option.
• Works Standalone: Yes.
• Key Features: 10GB/month free data, R.O.B.E.R.T. ad/tracker blocker, multiple free locations.

Hands-on experience

The free plan provides access to servers in over 10 countries, including the US and UK, which is perfect for occasional content unblocking. The built-in R.O.B.E.R.T. ad blocker is a standout feature, effectively cleaning up webpages and making browsing faster and more pleasant. I used it to watch several YouTube videos and was delighted to see it block all pre-roll ads.

Performance

For a free service, the speeds are very usable. While not as fast as the premium options, I could easily stream HD video without major buffering. The 10GB data cap is enough for a good amount of browsing or a few hours of streaming each month.

1.5. #5 – Proton VPN

Proton VPN‘s offer is simple but incredibly compelling: A completely free plan with no data limits. This service is run by the same team of scientists and engineers behind the encrypted email service, Proton Mail. Their commitment to privacy is unquestionable, making their free offering a trustworthy choice.

• Free or Paid: Offers a truly unlimited free plan and a premium option.
• Works Standalone: Yes.
• Key Features: Unlimited data on the free plan, from a highly reputable, privacy-focused company.

Hands-on experience

The Firefox add-on is clean, simple, and gets straight to the point. The interface is not cluttered with features; it’s designed to get you connected securely. The free plan allows you to connect to servers located in three countries: the United States, the Netherlands, and Japan. You simply pick one and connect. It’s a no-fuss, reliable experience.

Performance

As a free service, you can expect speeds to be slower than on their paid plans, especially during peak times. In my tests, it wasn’t fast enough for a smooth 4K streaming experience, but it was perfectly fine for standard-definition video and general web browsing. The key benefit is that you can browse for hours without ever worrying about a data cap.

2. Firefox add-on vs. full VPN app (what’s the difference?)

Before we dive into specific recommendations, it’s essential to understand a fundamental difference that applies to the entire world of browser VPNs. The “VPN add-on” you install in Firefox is a very different tool from the “VPN app” you install on your computer.

I often explain it like this: An add-on is like hiring a bodyguard to walk alongside you inside a specific building (your Firefox browser). A full app is like having a dedicated, armored car that transports you securely everywhere you go, protecting you from threats both inside and outside any building.

Here’s the difference at a glance:

Feature	VPN Add-on for Firefox	Full VPN App
Protection Scope	Firefox Browser Only	Entire Device
Primary Use	Quick Unblocking	Total Privacy & Security
Kill Switch	No	Yes (System-wide)
Protects Other Apps	No (e.g., Email, Games)	Yes (All apps)

Now let’s look at the practical details.

VPN Add-on (A Tunnel for Firefox)

• What it protects: It only secures the internet traffic that originates from within your Firefox browser. This is great for hiding your IP address when visiting websites or unblocking geo-restricted content in a Firefox tab.
• How it often works: Most add-ons are technically “encrypted proxies.” They route your browser’s web requests through a remote server. While this hides your IP from the websites you visit, it doesn’t always provide the same robust, end-to-end encryption as a full VPN app.
• What it leaves exposed: Any application on your computer outside of Firefox. Your traffic from other browsers remains unprotected. This includes your email client, like Thunderbird or Outlook. Your music streaming app, video games, and file-sharing software are also visible to your internet service provider (ISP).
• Best For: Quickly unblocking a website at school or work, changing your virtual location for browsing-related tasks, and adding a basic layer of protection within Firefox.

Full VPN App (A Fortress for Your Entire Device)

• What it safeguards: It encrypts all internet traffic originating from your entire computer. It doesn’t matter what application is sending or receiving data. If it connects to the internet, it’s protected by the VPN’s secure tunnel.
• How it works: A full app installs at the operating system level. It uses highly secure and audited protocols like OpenVPN or WireGuard to create a virtual “armored tunnel” for all your data.
• What it secures: Everything. This is the solution I personally use when connecting to any network I don’t 100% trust, like at a hotel or airport. It ensures that my financial information, private messages, and all other sensitive data are completely shielded from potential eavesdroppers.
• Best For: Comprehensive, always-on privacy, securing your connection on public Wi-Fi, anonymous torrenting, and protecting your entire digital life, not just your browsing history.

3. Mozilla VPN vs. third-party add-ons

For Firefox users, there’s a unique and compelling option to consider: Mozilla’s own VPN. This immediately raises the question: “Why would I use anything else?” As someone who deeply respects Mozilla’s mission, I’ve spent a lot of time with their VPN to give you an honest, direct comparison.

The first and most important thing to understand is that Mozilla VPN is a full, standalone VPN application, not just a browser add-on. It competes directly with the full desktop apps from providers like NordVPN and ExpressVPN, not their lightweight browser extensions. To help you understand the trade-offs, here’s a direct comparison between Mozilla’s offering and the top third-party VPNs.

Feature	Mozilla VPN	Top 3rd-Party VPNs
Type	Full VPN Application (Protects your whole computer)	Offer both a Full VPN App and a separate, lightweight Browser Add-on.
Technology	Uses Mullvad’s server network (excellent for privacy) and the modern WireGuard protocol.	Use their own massive proprietary networks with multiple protocol choices (WireGuard, OpenVPN, etc.).
Privacy Focus	Extremely High. Leverages Mullvad’s audited no-logs policy, one of the best in the industry.	Very High. Top providers have also undergone independent no-logs audits.
Server Network	Smaller, but very high-quality (~500+ servers in ~30 countries).	Much Larger. Thousands of servers in 90+ countries, offering more connection options.
Price	Competitive, simple monthly/yearly fixed price.	Often cheaper with long-term (2-3 year) deals and frequent promotions.
Ecosystem	A standalone privacy product.	Often part of a larger security suite (password manager, cloud storage, etc.).

Mozilla VPN is a fantastic, highly trustworthy, and privacy-focused VPN application. By partnering with Mullvad, they’ve built their service on one of the most respected foundations in the privacy community. Using it is a great way to directly support the non-profit organization that creates the browser you love.

However, it’s not a browser add-on – it’s a full-fledged program. If your goal is comprehensive security, it’s a top-tier choice.

Providers like NordVPN or ExpressVPN, on the other hand, offer more flexibility. They give you a much larger server network (which is better for unblocking niche content). And the choice between using their powerful full app or their convenient browser-only add-on.

Which path is right for you?

This checklist should make your decision clear.

• Choose Mozilla VPN if: You want a simple, highly private, full-featured VPN to protect your whole computer and want to directly support the creators of Firefox.
• Choose a Premium VPN (like ExpressVPN/NordVPN) if: You need a massive server network with more country options, want the flexibility of both a full app and a browser add-on, or are already subscribed to your other devices.
• Choose a Freemium Add-on (like Windscribe) if: Your privacy needs are occasional (like unblocking a single website), and you’re comfortable with data or server limitations, but still want a reputable provider.

4. How to spot a dangerous free VPN add-on

The Mozilla Add-ons store is generally better curated and safer than Chrome’s, but that doesn’t mean risky extensions don’t slip through the cracks. As a privacy-conscious Firefox user, it pays to be extra vigilant. Based on my experience vetting these tools, here is a simple safety checklist to use before you install any unknown VPN add-on.

1. Look for the "recommended" badge

This is the single most important trust signal on the Mozilla Add-ons store. Mozilla has a team of curators who manually review add-ons for security, functionality, and user experience. If an add-on has the “Recommended” badge, it means it has passed a thorough security review. I give immense weight to this badge, and you should too.

2. Check the permissions (Firefox makes it easy)

Before you finalize the installation, Firefox will show you a clear, easy-to-read pop-up listing the permissions the add-on is requesting. Read it carefully. Does a simple proxy really need permission to “Access browser tabs” or “Access browser activity during navigation”? If the permissions feel too broad for the add-on’s stated purpose, it’s a major red flag. Click “Cancel.”

3. Read the privacy policy

A trustworthy developer will always provide a link to their privacy policy on their add-on page. I make it a rule to never install an add-on that doesn’t have one. When you read it, look for clear language. A good policy will state plainly, “We do not log your browsing activity.” Vague language like “we may collect anonymized usage statistics” is often a warning sign.

4. Check the user reviews and version history

Look beyond the simple star rating. Scroll down and read some of the recent reviews. Are users complaining about recent updates breaking the add-on or a sudden influx of ads? Also, look at the “Version information” section. A good developer will be actively maintaining their add-on with regular updates and bug fixes. An add-on that hasn’t been updated in two years is likely abandoned and could have unpatched security vulnerabilities.

5. How to install and use a VPN add-on in Firefox

One of the best things about Firefox add-ons is how seamlessly they integrate into the browser. The installation process is quick, simple, and takes less than a minute. Here are the five easy steps to get a VPN add-on up and running in your Firefox browser.

Step 1: Open the official Mozilla add-ons store

First, open your Firefox browser. You can either go directly to addons.mozilla.org or click the menu button (the three horizontal lines in the top-right corner) and select “Add-ons and themes.”

Step 2: Search for your chosen VPN

In the “Find more add-ons” search bar, type the name of the VPN you’ve decided to use (e.g., “Windscribe” or “Proton VPN”).

Step 3: Click "Add to Firefox"

From the search results, find the official add-on from the provider. You’ll see a prominent blue button that says “Add to Firefox.” Click on it.

Step 4: Review permissions and add

A pop-up window will appear, clearly listing the permissions the add-on requires to function. After you’ve reviewed them and are comfortable, click the “Add” button. Firefox will install the add-on.

Step 5: Click the icon to log in and connect

The add-on’s icon will now appear in your Firefox toolbar. Click on it. You may need to log in with your account credentials. Once logged in, you’ll see a simple interface. Just choose a server location from the list and click the main “Connect” button.

And that’s it! Your Firefox browser is now protected. The icon in your toolbar will typically change color to indicate that you are actively connected and secured.

6. FAQ about the best VPN Extensions for Firefox

Here are the direct answers to some of the most common questions Firefox users have about VPNs and browser add-ons.

7. Conclusion

Choosing the right VPN for Firefox is about balancing the convenience of a browser add-on with the level of security you truly need. For a community that values privacy, making an informed decision is paramount.

To ensure your browsing remains secure and private, here are the key takeaways from our guide:

• An add-on only protects your browser, while a full app (like Mozilla VPN or a third-party client) protects your entire device.
• Mozilla VPN is a fantastic, highly private option if you need a full VPN and want to support the Firefox ecosystem.
• ExpressVPN offers the best add-on, which cleverly and securely controls its more powerful desktop app.
• Always use our safety checklist when considering a free, unknown add-on to avoid privacy risks.

For quick website unblocking and enhanced browser privacy, a reputable add-on is a perfect companion for Firefox. For comprehensive, always-on security that aligns with a privacy-first philosophy, a full VPN application is always the superior choice. Now that your browser is secure, discover ways to safeguard the rest of your online presence. Explore the complete library of Best VPN guides from Safelyo for comprehensive reviews and security advice.