Before choosing a VPN extension
Many VPN add-ons require powerful permissions like “control browser proxy settings” and “access your data for all websites,” which increases the importance of trusting the vendor and reading the privacy policy.
Mozilla can block add-ons that risk user privacy/security or violate policies, and a blocked extension can be disabled in Firefox without the user being able to override the block.
If another extension modifies Firefox proxy settings (proxy managers, some privacy/security tools), it can interfere with VPN extension behavior because VPN extensions often rely on setting proxy rules.
Top 5 VPN “extensions” for Firefox
- These five are widely discussed as privacy-focused, audited, or popular mainstream VPN brands, and they are commonly considered in “top no-logs VPN” lists that emphasize third-party verification.
- Important: for several providers, the Firefox extension may function as a browser-only tunnel/proxy or as a controller for the desktop app, so the article should explicitly state whether protection is “Firefox-only” or “whole device.”
1) ExpressVPN (Firefox extension)
- The main user value is convenience and quick server switching from the browser, but users should confirm whether the extension is browser-only or depends on a desktop app for full VPN protection and kill-switch behavior.
- For data safety claims, reference the importance of third-party verification (audits/real-world validation) rather than marketing language like “100% anonymous.”
- For restrictive networks, users should understand that access reliability may vary due to local blocking and that rotating servers/settings may be required.
2) NordVPN (Firefox extension)
- NordVPN is frequently cited as having multiple no-logs audits (including audits referenced as occurring in 2019, 2021, and January 2024), which is relevant for “privacy proof” sections.
- Readers should still treat “no-logs” as a policy verified within an audit scope, not an absolute guarantee, and should combine it with secure account settings (strong password + MFA).
- If the Firefox extension is used without the full app, clarify what it does and does not protect (typically Firefox traffic only), and how that impacts torrenting, other browsers, and system apps.
3) Proton VPN (Firefox use with app + privacy posture)
- Proton VPN is commonly referenced as having an independent audit verifying no-logs claims and as publishing a transparency report, which helps support a “trust and legal requests” section.
- Users should understand that legal requests and compliance outcomes depend on jurisdiction and on what data is actually retained, so transparency reporting and audit scope matter.
- For best results, position Proton VPN as a privacy-first choice where full protection and leak controls are typically strongest in the dedicated app rather than relying on a browser-only approach.
4) Surfshark (Firefox extension)
- Surfshark is commonly mentioned as having third-party audits and operating a RAM-only server approach, which is relevant to “data minimization” explanations.
- When discussing features like ad/tracker blocking, note that these can improve comfort but do not replace anti-fingerprinting or account-level privacy choices.
- In technical sections, remind users that extension behavior can be impacted by proxy-setting conflicts with other add-ons.
5) Mullvad (Firefox + app approach, privacy model)
- Mullvad is often highlighted for a privacy-forward account model and is frequently listed among verified/audited no-logs VPN options, which is useful in a “privacy by design” section.
- In a Firefox-extension-focused article, it’s fair to position Mullvad as “best for privacy model + full VPN app usage,” since browser extensions alone often can’t provide full-device leak protections.
- Set expectations clearly: a privacy-focused VPN may be excellent for threat-modeling, but streaming/unblocking reliability can be less consistent than “streaming-first” providers.
Firefox VPN comparison table
| VPN | Firefox extension availability | What it protects (common model) | WebRTC leak protection | Notable extension features (examples) | Notes / limitations |
|---|---|---|---|---|---|
| ExpressVPN | Mozilla Add-ons listing exists | Often works as a browser extension that can manage/privacy-protect browser traffic and integrates with the service | Explicitly marketed WebRTC blocking and leak protection (DNS/IPv6/WebRTC) | Location/geolocation spoofing described by provider; WebRTC blocking controls | Strong when used as intended; still test leaks because browser privacy depends on settings + environment |
| NordVPN | Provider documents a Firefox proxy extension | Presented as a “proxy extension” for Firefox; focuses on browser sessions rather than full-device coverage | Provider states extension can disable WebRTC to prevent leaks | CyberSec feature in extension (ad/malware blocking) is described in Nord documentation and reviews | Nord explicitly frames it as a proxy extension; may not equal full VPN app protection for all traffic |
| Proton VPN | Mozilla Add-ons listing exists (Proton VPN extension) | Browser protection for browsing sessions; marketed as “one click” privacy in Firefox | Not highlighted in the snippet as “WebRTC blocking”; users should verify via leak tests and settings | Auto-connect on browser start; server selection; Secure Core (double-hop) mentioned in listing | Treat “extension protects browser” as the default assumption and test WebRTC/DNS behavior in your setup |
| Surfshark | (Not pulled from sources in this chat for Firefox listing) | Typically positioned as an extension + full VPN app ecosystem, but exact Firefox extension capabilities should be verified on official pages before publishing a table row with hard claims | Not verified here for Firefox-specific WebRTC toggle; assume “needs testing” unless confirmed | Privacy positioning and features vary; verify Firefox add-on permissions and features on the official listing before recommending | If you plan to publish: add citations from Surfshark’s official Firefox add-on page (not available in sources above) |
| Mullvad | (Not pulled from sources in this chat for Firefox extension listing) | Commonly used as a full VPN app; Firefox extension capabilities (if any) must be verified before claiming features | Not verified here for Firefox-specific WebRTC blocking; assume “needs testing” unless confirmed | Privacy-first account model is often cited generally, but extension feature claims require official add-on sources | For Firefox-focused articles, treat Mullvad primarily as “best via app,” and only list an extension if you can cite Mozilla Add-ons or official docs |
Technical safety and limitations (must include)
- Extension vs app scope: many Firefox “VPN extensions” work by controlling Firefox proxy settings, meaning they may not protect traffic from other apps or browsers on the device.
- Proxy conflicts: if another extension or a manual Firefox proxy configuration is present, it can break VPN extension functionality because both compete over proxy rules.
- WebRTC leak risk: WebRTC can reveal IP information in some scenarios, so a guide should include how to test and how to mitigate it in Firefox.
- WebRTC mitigation steps (Firefox):
- Open about:config, search media.peerconnection.enabled, set to false if you must fully disable WebRTC for privacy testing.
- Alternative advanced settings exist (e.g., proxy-only modes) but should be presented carefully because they can break calls/video apps and aren’t always user-friendly.
- Leak testing checklist to include in the article:
- Run a WebRTC leak test (to see if public/local IPs are exposed).
- Verify extension permissions and understand that “access your data for all websites” means the add-on can technically read/modify page data.
Rules of use (usage policy section)
Use only official sources: install extensions from Mozilla Add-ons, because Mozilla can block extensions that violate policies or endanger privacy, and blocked add-ons may be disabled by Firefox.
Avoid sideloading “repacked” extensions from third-party sites, especially if an add-on is region-blocked, because that increases malware and tampering risk.
Follow provider and website terms: VPN use can violate some platforms’ terms (common with streaming/banking anti-fraud systems), and the service may challenge logins or restrict access.
Legal constraints and disclaimers (must be explicit)
A VPN is not “automatic anonymity”: sites can still identify users by logins, cookies, and fingerprinting, even if the IP address changes.
Legality varies by jurisdiction, and compliance outcomes depend on provider jurisdiction plus what data is retained (so audits and transparency reporting are relevant evidence, not just marketing).
Any publication should include a clear “not legal advice” note and recommend users verify local laws and employer policies before relying on a VPN in restricted environments.
User data security (what to recommend)
Treat extension permissions as sensitive: if an add-on can “access your data for all websites” and “control browser proxy settings,” it must be from a trusted vendor with clear privacy documentation.
Prefer providers with third-party audits and transparency reporting, because they provide stronger external signals than unverified “no logs” claims.
Harden the account: enable MFA where available, use a unique password, and remember that payment methods can link identity even when browsing traffic is encrypted.