HomeWhy Speed Tests Disagree

Why VPN Speed Tests Disagree

One review crowns NordVPN. The next says Surfshark. A third quotes download numbers five times higher than both. They're mostly not lying — here's what's actually going on, and how to read any “fastest VPN” claim without getting played.

The same VPN, five different answers

Search “fastest VPN” and you'll find reputable sites that flatly contradict each other. For the exact same provider, one review reports an average download around 270 Mbps; another quotes well over 1,200 Mbps. One test names NordVPN the winner of a head-to-head; the next hands it to Surfshark. If these were measuring the same thing, the numbers would line up. They don't — and the reason isn't usually fraud.

It's that “fastest” is a conditional result dressed up as a fact. A VPN speed figure is the output of one specific test, run under one specific set of conditions, on one specific day. Change almost any input — the city you connect to, the protocol, the time of day, the tester's own internet line — and the ranking can flip. The number is real. The word “fastest” bolted onto it is the part that's overselling.

There is no single “fastest VPN”

Asking “which VPN is fastest?” is like asking “which car is fastest?” without naming the track, the weather, or the driver. The honest answer is always fastest under these conditions — and almost nobody prints the conditions next to the headline.

That's the gap that lets two careful, well-meaning reviewers reach opposite conclusions. Neither has to be wrong. They simply tested different things and gave the results the same label.

The six variables that decide who “wins”

Almost every disagreement between speed tests traces back to one of these six inputs. Each one can change not just the numbers but the ranking:

VariableWhy it flips the result
Server endpoint & distance“Fastest” usually means fastest to the server the tester happened to pick. Provider A may win to a London endpoint and lose to a São Paulo one. Whoever has a nearby, well-connected server wins that particular test — and networks differ wildly by country.
ProtocolWireGuard, NordLynx and Lightway beat older OpenVPN/IKEv2 by large margins. Two sites testing different default protocols can get different winners for the same two providers. Protocol choice often moves the number more than the brand does.
Time of day & server loadA server at 8pm peak and the same server at 3am are effectively two different servers. Congestion can swing throughput more than the choice of provider.
The tester's own line & ISP peeringA 100 Mbps home connection caps every VPN at 100 Mbps — you're measuring the line, not the tunnel. A multi-gigabit datacentre exposes the tunnel's true ceiling (which is why those numbers look huge). And how well your ISP peers with the VPN's network changes the result again.
Measurement toolOokla Speedtest, a raw file download, and iperf produce different absolute numbers — and sometimes a different ordering — for the identical connection.
Sample sizeOne test is noise. VPN speeds vary minute to minute; a single screenshot can land on a lucky or unlucky run. Only an average over many tests means anything — and most reviews quote a single shot.

Stack these together and the surprise isn't that reviews disagree — it's that any two ever match.

The part affiliate sites can't tell you

There's one more reason rankings diverge, and it has nothing to do with networking. Most VPN review content is funded by affiliate commissions, and payouts differ sharply between providers — some exceed $100 per signup. When the highest-paying VPN also happens to be crowned “fastest,” it's worth asking which came first.

You can usually spot it. The tells:

We take affiliate commissions too — it's how this site is funded, and we say so plainly. The difference is that our rankings can't be bent to match a payout: the speeds are collected by an automated system that has no awareness of which provider pays more, tests both identically, and runs continuously. The code measures; it doesn't negotiate.

How to read any VPN speed claim

You don't need a lab to sanity-check a “fastest VPN” headline. Before you trust a ranking, ask five questions:

  • Are the conditions stated? Which server city, which protocol, which test tool? No conditions, no credibility.
  • One test or an average? A single number is a snapshot of one moment. An average across many tests is a measurement.
  • How fresh is it? VPN networks change constantly. A result from months ago describes a server that may no longer exist.
  • Were all providers tested the same way? Same hardware, same protocol family, same day — or apples vs oranges?
  • Can you see the raw data? Continuously-updated figures beat a single screenshot you have to take on faith.

If a page can't answer these, treat its “winner” as an opinion, not a measurement.

How we sidestep the whole mess

We can't tell you what speed you'll get at home — that depends on your broadband, your distance, and your ISP. What we can do is remove every variable except the VPN itself. Surfshark and NordVPN are tested on the same hardware, with the same protocol, by the same automated process, continuously — over 57,825 tests across 270 server locations and counting.

That doesn't produce a single mythical “fastest VPN.” It produces something more useful: a like-for-like comparison where, if one provider is faster in the city you actually connect to, you can see it — and trust that nothing but the VPN was different. These are datacentre-measured ceiling speeds, not a home-broadband guarantee; their value is the apples-to-apples comparison.

See the live head-to-head → How we test →

Frequently Asked Questions

Is NordVPN faster than Surfshark?+
It depends entirely on the conditions — which is exactly why reviews disagree. Both run the WireGuard protocol (NordLynx on NordVPN) and both are among the fastest VPNs available, so the winner changes with the server city, the time of day, and the tester's own connection. Rather than crown one, we test both identically and continuously and show the result per location, so you can see which is faster in the regions you actually connect to. See the live comparison →
Why is my VPN slower than the reviews say?+
Because most high headline numbers are measured from a datacentre with a multi-gigabit uplink — they show the tunnel's ceiling, not what your home line can deliver. Your real speed is capped by your own broadband (a 100 Mbps line can never exceed 100 Mbps through any VPN), your Wi-Fi, your distance to the server, and time-of-day congestion. The review isn't necessarily wrong; it's measuring a different thing than your living room.
Which VPN speed test should I trust?+
Trust the ones that show their work: stated test conditions (server, protocol, tool), averages rather than single shots, recent dates, the same method applied to every provider, and visible raw data instead of a lone screenshot. A confident ranking with none of that is an opinion. Be especially wary when the same VPN is declared best at everything for everyone — that's a sign the ranking may be tracking affiliate payouts rather than performance.
Does the VPN protocol affect speed?+
Significantly. Modern protocols — WireGuard, NordLynx and Lightway — are much faster than older OpenVPN and IKEv2. The difference is often larger than the gap between two providers, which is why a review testing OpenVPN can reach a different “winner” than one testing WireGuard. We test on WireGuard throughout so the comparison stays consistent.