Proton VPN vs Surfshark: Handling of WebRTC and Browser Leaks

WebRTC and browser leaks trip up a lot of VPN users. You connect, think your IP is hidden, but a quick check shows your real address popping out. WebRTC—meant for real-time stuff like video calls—grabs your local and public IPs through STUN servers, even over UDP tunnels. Browsers can leak via DNS queries, canvas fingerprinting, or sloppy JavaScript. Proton VPN and Surfshark both tackle this, but they go about it differently. Let's break it down without the fluff.

What Makes WebRTC Tricky

WebRTC kicks in automatically in Firefox, Chrome, and Edge if you don't tweak settings. It sends ICE candidate reports that include your real IP. VPNs route most traffic fine, but if the app doesn't block those UDP packets or mDNS queries, leaks happen. Browser leaks pile on: unencrypted DNS requests hit your ISP, or sites fingerprint your setup via hardware info. A solid VPN plugs these at the network level. No need for manual browser fiddling every time.

Proton VPN's Leak Protections

Proton VPN starts with basics that matter. Their kill switch cuts internet if the tunnel drops—no leaks during reconnects. They own their DNS servers, so queries stay inside the VPN. For WebRTC, Proton blocks it outright in their apps. They use firewall rules to drop STUN traffic on ports 3478 and 5349, UDP and TCP. Tests on sites like browserleaks.com usually show no local or public IP exposure when connected.

Browser-specific stuff? Proton pushes users to their extension, which proxies traffic and adds leak blocks. Without it, you might tweak Firefox's about:config (set media.peerconnection.enabled to false) or Chrome flags. But the core apps handle most cases. They run on a no-logs setup with Secure Core servers that double-hop, reducing leak surfaces. IPv6 gets disabled by default too, dodging dual-stack leaks. Overall, Proton feels deliberate—built by privacy folks who audit everything.

Surfshark's Approach to Leaks

Surfshark leans into app-level fixes. Their kill switch has modes: standard and "permanent," which locks you out until reconnect. DNS is locked to their servers, with options for custom ones. WebRTC protection? It's a toggle in settings, on by default. They modify the browser's WebRTC stack or block via system firewall—drops those ICE candidates before they escape. Expect clean results on ipleak.net: no IPs, no DNS slips.

Beyond that, Surfshark's CleanWeb feature nukes trackers and ads that often probe for leaks. It doesn't fully block WebRTC but cuts the scripts that trigger it. They support WireGuard and OpenVPN protocols, both tuned for leak resistance. MultiHop adds a bounce, like Proton's Secure Core. Surfshark shines in unlimited devices, so leaks don't spread across your setup. They test publicly and patch fast—recent updates fixed some UDP quirks.

Key Differences in Handling

Proton integrates leak blocks deeper into the protocol stack. No toggles needed; it's always on. Surfshark gives you control, which suits tinkerers but risks if you flip it off. Proton's open-source apps let you inspect the code—firewall chains explicitly drop WebRTC. Surfshark's are closed-source, but independent audits back their claims.

Browser leaks get similar treatment, but Proton edges out with netshield (their ad/tracker block) that fingerprints less. Surfshark's CleanWeb does the same, often more aggressively. Both handle IPv6 and DNS fine, but Proton rarely slips in edge cases like torrent clients with WebRTC enabled.

Side-by-Side Comparison

Common Pitfalls and Tests

Leaks sneak in via browser extensions overriding VPNs or IPv6 enabled. Both services warn about this. To check yourself, hit browserleaks.com/webrtc or ipleak.net. Look for public IP matching your VPN exit, not home. If WebRTC shows local IPs, something's off.

curl https://ipinfo.io/json  # Check public IP

webrtc.org/testing/       # Browser console test

about:webrtc              # Firefox status

Run these connected. Proton and Surfshark pass consistently. Avoid free WiFi tests—those amplify issues. Update apps; old versions leak more.

Final Thoughts

Both nail WebRTC and browser leaks better than most. Proton suits if you want set-it-and-forget-it with open-source trust. Surfshark fits if you like tweaks and extras like tracker blocking. Neither leaves you exposed in daily use, but verify with your setup. Leaks rarely happen if you stick to their apps and protocols. Pick based on your threat model—Proton for max audits, Surfshark for flexibility. Either way, you're covered where it counts.