"Turned on the VPN — pages take longer to load, video buffers." This is the most common complaint after installing a VPN. Good news: in most cases it's fixable in a couple of minutes by changing one or two settings. Bad news: sometimes the problem isn't the VPN, it's the internet itself.
Let's go through the 7 main reasons a VPN feels slow and what to do about each.
Reason 1: Distant server
The most common one. If you're in London and you connect to a server in the US — every request has to fly a few thousand kilometers and come back. The speed of light in fiber sets a physical floor: you'll never get under 100 ms latency to America from Europe.
Fix: pick a closer server. For everyday use — your country or a neighboring one. For specific tasks (opening a US site) — the right region, but that's no longer "fast VPN", that's "VPN for a job".
Reason 2: Overloaded server
If 1000 users are sharing one server simultaneously, your speed gets divided across them. This is a typical problem with free VPNs: few servers, lots of users.
Fix: in the app, pick a server with low load (good apps show an indicator: 30%, 70%, 90%). Or switch to a paid service with more servers and capacity headroom.
Reason 3: Old protocol
If your settings show OpenVPN — or worse, L2TP — speed will be lower than on modern WireGuard. The difference can be multi-fold: WireGuard is significantly more CPU-efficient.
Fix: in the protocol settings pick WireGuard. If it's unavailable (rare cases where the ISP blocks it) — IKEv2 as a second option. OpenVPN as a fallback for very strict networks.
Reason 4: Internet speed itself
Sometimes "slow VPN" is just slow internet, and the VPN simply makes it obvious. Run a speedtest first without VPN, then with VPN. If you get 5 Mbps without VPN too — the problem isn't the VPN.
Fix: if the internet is slow on its own — talk to your ISP or check the router. Even a perfect VPN won't make you faster than the underlying connection.
Reason 5: Wi-Fi at the edge
If your laptop is on Wi-Fi 10 meters and 2 walls away from the router, real speed can drop from 200 Mbps to 30. The VPN adds another 5–10% loss, and you go from "seems fast" to "clearly slow".
Fix: get closer to the router or plug in a cable. That's not a VPN problem, that's radio physics.
Reason 6: Antivirus and firewall
Some antivirus suites (especially "all-in-one security packages") inspect ALL of your traffic in real time, including the encrypted VPN channel. That doubles the load and slows things down noticeably.
Fix: add the VPN app to the antivirus exclusions. On Windows, check whether Defender has active deep packet inspection on network connections.
Reason 7: Time of day and ISP throttling
In peak evening hours — 7 PM to 11 PM — network load rises and ISPs start "shaping" specific traffic types. VPN traffic sometimes falls under this: the ISP sees an encrypted connection and throttles it.
Fix: try changing the port (most VPNs can run on 443 or 80, masquerading as regular HTTPS). If the morning vs evening difference is huge — it's almost certainly ISP throttling.
Quick diagnostic: 5-minute checklist
If your VPN suddenly got slow, walk through this short list:
- Run a speedtest without VPN — measure baseline.
- Run a speedtest with VPN, on the nearest server, on WireGuard — should be 80–95% of baseline.
- If lower — try a different server in the same country.
- If still slow — switch the protocol.
- If that doesn't help — disable the antivirus for 1 minute and re-test. If the speed comes back, the antivirus is in the way.
In 90% of cases the problem reveals itself at one of these steps.
Realistic speed expectations
Sometimes "VPN is slow" is just inflated expectations. Realistic numbers:
- Near server, WireGuard: 85–95% of baseline. On 100 Mbps — 85–95 Mbps through VPN. That's normal.
- Distant server (across an ocean): 50–70% of baseline. Not because of a bad VPN, because of distance.
- OpenVPN instead of WireGuard: 20–40% less than what you'd get on WireGuard. That's the protocol.
- Free VPN: 10–30% of baseline — typical result.
VPN is REALLY slow: things you may not have tried
If all the steps above didn't help and the VPN gives 5 Mbps on a 100 Mbps line — there are rare but real causes:
- MTU issues. If the tunnel has the wrong MTU set, packets get fragmented and speed drops catastrophically. Try setting MTU to 1400 or 1380 in settings.
- IPv6 leak. Sometimes part of your traffic goes over IPv6 around the VPN while the VPN itself only handles IPv4. dnsleaktest.com has a check for this.
- Double NAT. If you have a router behind another router (typical in dorms or shared apartments), the VPN may struggle. Fix — configure bridge mode or put the VPN on the first router.
- Corporate proxy. Work computers may have a corporate proxy that intercepts HTTPS — incompatible with a VPN. Only solvable through your IT team.
If the VPN doesn't connect at all
That's a different problem, covered separately — VPN not connecting.
Bottom line
VPN speed is a combination of factors: distance to the server, server load, protocol, your own connection. In most cases setting the right protocol and picking a near server fixes it. If you're seeing a speed drop of more than 30% — time to switch to a better service.
VolnaLink VPN runs servers with capacity headroom and supports all modern protocols — typical speed loss 5–12% of your baseline. Try it free, no card required.