Once a VPN is on, data leaving a device no longer goes straight to its destination. It is encrypted, sent to the VPN server, unwrapped there, and only then passed on. Replies take the same path back.

So a VPN always makes the internet a little slower. The question is not whether it slows down, but whether the slowdown is reasonable.

Three sources of slowdown

  • Extra distance. A VPN server on another continent adds hundreds of milliseconds to every request, even if the site you want is in the same city.
  • Encryption work. The device must encrypt and decrypt every packet. A modern laptop barely notices; an old router running a VPN for the whole home notices a great deal.
  • Server load. Free VPN servers, or popular ones at peak times, are shared by thousands of people at once.

Measure fairly

Run a speed test without the VPN, then with it, at the same time and from the same place. Do it two or three times. Without a comparison it is hard to tell whether the VPN is slow or the connection itself.

Fix order

  • Choose the nearest server that still meets your need. If the VPN is for safety on public Wi-Fi, a server in your own or a neighbouring country is enough.
  • Switch protocol. Most VPN apps offer several. Modern protocols such as WireGuard are generally much faster than OpenVPN, especially on phones.
  • Try UDP if available. TCP mode gets through strict networks more easily, but is slower and stutters more on unstable connections.
  • Change server if the chosen one is busy. Many apps show a load percentage.
  • Turn on split tunnelling if the VPN is only needed for certain apps.

Work VPNs

Work VPNs are often set up so all traffic passes through the office, including video and social media. If the office connection is small, every employee working from home shares the same narrow path.

This isn't something employees can change themselves. What you can do is report it to IT with data, speeds with and without the VPN, times it happens, and ask whether split tunnelling can be enabled for traffic unrelated to work.

When the symptoms are odd, not just slow

If with the VPN some sites won't open at all, pages stop halfway, or only large uploads fail, the cause is often packet size rather than speed. The explanation and how to check are in the guide to what MTU is. Lowering the MTU in the VPN app's settings usually resolves it.

VPN on the router

Running a VPN on the router protects every device at once, but home routers rarely have a strong enough processor. Speed that stays stuck at a low figure whatever your plan is a sign of an overwhelmed router. For most people, a VPN on each device is faster.

Conclusion

A small drop is normal. If it is excessive, pick the nearest server, switch to a modern protocol, use UDP, and use split tunnelling. If some sites won't open, check MTU. For a work VPN, take the data to IT.

Frequently asked questions

How much slowdown is normal on a VPN?

With a server in the same or a neighbouring country and a modern protocol, a 10–30% drop is normal. If speed falls by more than half, something can usually be fixed: server distance, protocol, or server load.

Can a VPN make the internet faster?

Rarely, and only in special cases, for example if the provider throttles a particular kind of traffic, or its route to a service is poor. Normally a VPN always adds overhead.

What is split tunnelling?

A setting that sends only some traffic through the VPN, say, only work systems, while the rest goes straight to the internet. Video, updates, and ordinary browsing then don't slow down.