How much does a VPN slow your internet?
On a nearby server, expect to lose roughly ten to thirty percent of throughput and to gain the round trip to that server in latency. Distance, server load and your own hardware account for far more of the variation than the protocol or the encryption does.
4 min read
Yes, a VPN costs something. Anyone claiming otherwise is either selling something or measuring badly. The useful question is how much, and where it goes, because three of the four sources are things you can do something about.
Where the loss comes from
Distance. The largest factor by far, and the most often misattributed to the protocol. Your packets travel to the server before going to their destination. A server on another continent adds 150 milliseconds or more, and latency translates directly into reduced throughput for anything that waits for acknowledgements.
Server capacity. A shared exit divides its uplink among everyone on it. Evening peaks on a popular location are noticeably worse than the same server at six in the morning.
Protocol overhead. Each packet carries the tunnel's headers, so slightly less of each packet is your data. This is a few percent, not a third.
Encryption. On a modern phone or laptop, negligible. On a router or a streaming stick, it can be the whole bottleneck.
Notice that the two people usually blame — overhead and encryption — are the two smallest on most hardware.
What a normal result looks like
| Measure | Nearby server | Another continent |
|---|---|---|
| Download | 10 to 30 percent lower | 40 to 70 percent lower |
| Upload | 10 to 30 percent lower | Similar or worse |
| Ping | Plus 5 to 25 ms | Plus 120 to 250 ms |
| Jitter | Similar | Higher |
Measure your own with the speed test: once with the tunnel down, once with it up, against the same test server, wired rather than over Wi-Fi. Without that baseline every conclusion is a guess.
Why fast lines lose proportionally more
A 1,000 Mbps connection through a tunnel often lands at 300 to 600 Mbps, while a 50 Mbps connection through the same tunnel loses almost nothing.
The reason is that the loss is largely fixed work per packet — encryption, framing, context switches — and a fast line means far more packets per second. At 50 Mbps the hardware is idling; at gigabit it is not. On any device where the CPU is modest, gigabit is where that shows.
What you can actually recover
Pick a closer server. The single largest lever, and it costs nothing. The server list is worth reading by latency rather than by flag.
Use WireGuard rather than OpenVPN, if the client offers a choice. The gap is widest on hardware without AES acceleration, which describes phones, tablets, TV boxes and routers.
Test a second server in the same country. Congestion is per-server, and a neighbour is often much faster at peak times.
Fix your MTU. If large transfers stall while small requests are fine, the problem is not throughput at all — it is packets being silently dropped for being too big.
Wire the device. Wi-Fi loses more than most tunnels do, and it is the variable most people never control for.
What you cannot recover
The speed of light. A round trip to a server 8,000 kilometres away takes at least 80 milliseconds and usually more, and no configuration changes that.
If you need a distant exit country, that latency is the price of the requirement rather than a fault in the service.
Bufferbloat, which is probably your real problem
Run a latency measurement while a download is saturating the link. If ping goes from 20 ms to 300 ms, your router is over-buffering, and that is what makes video calls stutter and pages feel slow regardless of any VPN.
Smart queue management on the router — cake or fq_codel on OpenWrt — fixes
it properly and improves the connection with the tunnel on or off. It is the
highest-value network change most households can make and it has nothing to do
with a VPN.
Is the trade worth it
For browsing, streaming and calls on a nearby server, the difference is usually imperceptible. Streaming 4K needs about 25 Mbps; a 200 Mbps line losing 25 percent still has 150 Mbps.
For very fast lines where you actually use the capacity, or for competitive gaming, the cost is real and worth thinking about — which is what split tunnelling exists for, and why turning the tunnel off for a particular session is a legitimate choice rather than an admission of defeat.
