· By IMRAN HOSSAIN
Quick answer: Follow a structured checklist: run controlled speed tests to isolate whether the slowdown is your ISP, the VPN server, or your device; switch protocol to WireGuard, check MTU and DNS, test another server and port, and apply platform fixes for desktop, mobile or router level to restore throughput. If you need background comparison, see Mullvad vs ProtonVPN.
- Key takeaways: test first, then change one variable at a time.
- WireGuard usually improves speed, but MTU, DNS and router limits often cause the largest real-world drops.
- Platform matters: fixes for Windows, Android, iOS, and home routers differ; route-level VPNs behave differently to app-level VPNs.
Why did my Mullvad or ProtonVPN connection become slow?
Slow VPN connections usually come from one of three causes, the VPN path, your local network, or your device, so test each to find the root cause.
Start by disconnecting the VPN and running the same download/upload test, then reconnect to the VPN to compare. If your non‑VPN speed is high, the problem is in the VPN path: server load, protocol mismatch, VPN features like Mullvad Multihop or ProtonVPN Secure Core, or ISP shaping. If both are slow, check your modem, router, Wi Fi congestion and ISP status. Collect baseline numbers with Speedtest.net and a second test like testmy.net to avoid single-site bias. Keep one variable change per test, and collect traceroute output when you see high latency or packet loss. If you use PureVPN, this guide shows step by step speed tests and fixes: Fix PureVPN Slowdowns: Speed Tests and Optimization Tips.
Which protocol should I try first to fix slow VPN speed?
Try WireGuard first because it usually gives the best throughput and lowest latency on modern devices.
WireGuard is a modern VPN protocol that uses fewer CPU cycles than OpenVPN, so it often improves speeds on desktop and mobile. If WireGuard is not available or performs poorly, test OpenVPN UDP, OpenVPN TCP, then IKEv2. For Proton VPN, try turning on or off ProtonVPN Accelerator if available. For Mullvad, test Mullvad Multihop only if you need the extra routing, because it will reduce throughput. Document each test: protocol, server, and measured upload/download numbers. If changing protocol helps, keep it and re-run application activities like video calls or uploads to ensure practical improvements. More advanced: if your ISP blocks UDP, a TCP-based protocol can restore connectivity while reducing throughput.
How do I test if the VPN or my ISP is the problem?
Compare controlled tests with and without the VPN, and use traceroute or MTR to spot where packet loss or latency appears.
Step 1, run a non‑VPN speed test using Speedtest.net and a second site such as testmy.net to get baseline download, upload and latency. Step 2, connect to a nearby VPN server and repeat the same tests. Step 3, run traceroute and MTR to the same destination with and without the VPN. If loss appears after the VPN hop, the provider or chosen server is likely at fault. If loss happens before the VPN endpoint, the ISP or local network is the issue. For throttling suspicion, try an alternate port or WireGuard: many ISPs shape traffic on well-known ports. Save logs and share them with support if you open a ticket.
What decision framework should you use to pick fixes and when to switch providers?
Use a three-step decision tree: isolate, mitigate, decide whether to persist or switch, based on cost, frequency and impact.
Isolate: run the tests above and identify if the VPN path, ISP or hardware is responsible. Mitigate: if it’s a protocol or server issue, try WireGuard, a different server, or a different port. Decide: if problems persist more than twice a month and your work depends on consistent throughput, consider changing provider or moving VPN to the router. Keep cost and features in mind. For example, Mullvad charges €5 per month (Mullvad pricing page, 2026), which is a predictable cost for sustained use; when you compare to a provider with advanced routing features, use that number to calculate yearly spend. Hidden trade off: running VPN on the router protects every device but can reduce peak throughput depending on router CPU and whether the router supports WireGuard offload. For general troubleshooting strategies see Fix VPN Speed Drops.
How do I fix protocol, port and MTU issues on desktop?
Change protocol, switch UDP/TCP ports, and adjust MTU, testing one change at a time to restore desktop VPN throughput.
Windows and macOS clients let you switch between WireGuard, OpenVPN and IKEv2. If latency or throughput drops, try WireGuard first. If WireGuard fails, test OpenVPN UDP, then OpenVPN TCP using port 443 to evade strict firewalls. To diagnose MTU, use ping to send large packets and reduce MTU by 10 until fragmentation stops, then add 28 to stabilise. On Windows adjust MTU via netsh or network adapter properties; on macOS use ifconfig. Also check desktop CPU and antivirus: high CPU during encryption can bottleneck VPN speed. When desktop performance is constrained, consider split tunneling to exclude noncritical traffic from the tunnel. For desktop-level router replacements and persistent setups, read the router setup guide to move the VPN off the device and onto a dedicated gateway, see set up VPN router.
How do I fix Mullvad or ProtonVPN speed problems on Android and iOS?
On mobile, prefer the provider app’s WireGuard option, update the app, check background restrictions, and confirm cellular data settings.
Mobile operating systems aggressively manage background apps and battery, which can interrupt VPN daemons. Update the Mullvad VPN or Proton VPN app, enable always-on VPN (Android) or per-app VPN (iOS where available), and allow the app to run in background. On Android, disable battery optimisations for the VPN app; on iOS, use the IKEv2 or WireGuard profile when the app’s in-app tunnel is unstable. If mobile data is slow but Wi‑Fi is fine, compare carrier performance by disabling Wi‑Fi to isolate cellular limits. For app-specific streaming problems, use split tunneling to let heavy streaming bypass the VPN. If you run a podcast upload from mobile, estimate file sizes and test upload speeds to confirm practical performance before recording.
Is my home Wi Fi or router the likely cause and how do I fix it?
Your router or Wi Fi band often caps VPN throughput, so test wired connections and reduce Wi Fi contention before blaming the VPN.
First, test a wired Ethernet connection to the same device. If wired throughput is good and Wi Fi is slow, change to 5 GHz, move the router, and reduce nearby interference. Replace or update firmware for older routers; many consumer routers cannot handle high-speed encrypted tunnels because CPU and crypto hardware are limited. If you want provider-level protection for every device consider flashing a router with OpenWRT, AsusWRT or DD-WRT if supported, or buy a router with WireGuard hardware offload. When running VPN on the router, check whether the router model advertises VPN throughput limits. If you host services or use a seedbox, consult the seedbox performance advice in Seedbox Performance Benchmarks and compatibility with VPN routing in Use VPN with a seedbox.
Which one fits you: Mullvad fixes or ProtonVPN features?
Choose fixes based on your profile: privacy minimalist, streaming user, content creator, or remote worker, because each needs different balance of speed, multi-hop and features.
- Beginner and casual streaming user: Proton VPN plus a nearby low-load server because Proton VPN’s larger server park often reduces contention; see the streaming guide best VPN for streaming.
- Privacy minimalist with simple needs: Mullvad VPN and WireGuard, because Mullvad’s flat pricing and minimal account approach fits long-term predictable use, refer to the head-to-head ProtonVPN vs Mullvad.
- Creator uploading large files weekly: run VPN on a wired workstation or a router with hardware offload, and pick the provider with consistent uplink; compare to router-level options in set up VPN router.
- Small team or agency requiring remote access: use a provider with split tunneling and team features, and verify support responsiveness; for remote help use remote troubleshooting procedures.
Example: a solo creator uploading four 60 minute 128 kbps stereo MP3s per month should estimate around 230 MB monthly uploads, which is negligible versus typical broadband caps; focus on upload speed stability more than raw download throughput. If you need deeper provider comparisons, see Mullvad vs NordVPN and ExpressVPN vs Mullvad.
What common mistakes cause persistent VPN slowdowns?
Common mistakes include changing multiple settings at once, ignoring MTU and DNS, and running the VPN on underpowered routers or USB Wi Fi adapters.
Checklist of frequent errors: using multihop or Secure Core when not required, leaving DNS set to a slow resolver, not testing wired versus wireless, expecting mobile hotspots to match broadband, and running multiple security apps that conflict. Avoid changing both protocol and server in the same test. If you are troubleshooting streaming or gaming, do not assume a single site’s speed test represents all destinations; test multiple endpoints. If persistent issues remain after you follow the checklist below, capture logs and open a support ticket with the provider, including traceroute and MTR output. For broader VPN slow issues see Fix VPN Speed Drops.
Practical checklist to diagnose and fix Mullvad/ProtonVPN slow speed
- Disconnect VPN, run Speedtest.net and testmy.net for baselines.
- Reconnect to a nearby VPN server, test again, record results.
- Switch protocol: WireGuard, OpenVPN UDP, OpenVPN TCP, IKEv2, testing each once.
- Run traceroute and MTR to the same destination, with and without VPN.
- Change ports (443 or custom), disable multihop or Secure Core features.
- Test wired Ethernet to exclude Wi Fi; update router firmware or test alternative router firmware like OpenWRT when supported.
- Adjust MTU in 10 byte steps to remove fragmentation.
- Change DNS to a fast provider with DNS over HTTPS or DNS over TLS, or use the provider’s DNS if recommended.
- If issues persist, gather logs and contact Mullvad or ProtonVPN support with exact timestamps and tests.
Which is faster: Mullvad or ProtonVPN, comparison table?
Speed varies by server, protocol and location, but this summary highlights relative strengths and common limits to help you decide a fix path.
| Provider | Price range | Best for | Key strengths | Main limits |
|---|---|---|---|---|
| Mullvad VPN | €5 per month | Privacy minimalists, predictable cost | Simple account model, WireGuard support, multihop option | Smaller server network, multihop reduces speed |
| Proton VPN | Free to paid tiers (varies) | Streaming and varied server options | Larger server network, Secure Core, Accelerator feature | Some advanced features reduce throughput, plan-dependent limits |
When should you contact Mullvad or ProtonVPN support?
Contact support after you run baseline tests, switch protocols, and capture traceroute or MTR logs that show the slowdown remains on the provider side.
Support can confirm server outages, provide alternative endpoints, or advise on provider features such as Mullvad Multihop or ProtonVPN Accelerator. Before opening a ticket collect these items: timestamps, server name and country, protocol used, speedtest links, traceroute or MTR output, and whether you tested wired versus wireless. If you run a router-based VPN, include router model and firmware version. For more complex migrations or alternatives see comparisons such as NordVPN vs ExpressVPN or NordVPN vs PureVPN.
FAQ
Below are common voice‑search style questions and short direct answers to help you quickly act.
- Why is ProtonVPN so much slower than my regular connection? Direct answer: ProtonVPN adds routing and encryption overhead and may route you through distant servers, so try a nearer server, switch to WireGuard, and check server load.
- Does Mullvad slow down streaming? Direct answer: Mullvad can slow streaming if you use Multihop or a distant server; pick a low‑load nearby server and enable split tunneling for streaming apps if available.
- Is WireGuard always faster than OpenVPN? Direct answer: Not always, but often; WireGuard is more efficient, so try it first, then validate with real uploads or video calls to confirm.
- Can changing DNS improve VPN speed? Direct answer: Yes, slow DNS resolution causes page load delays; switch to a fast resolver with DNS over HTTPS or use the provider’s DNS setting in the app.
- Should I run VPN on my router to improve speeds? Direct answer: Only if your router has sufficient CPU or WireGuard offload; otherwise a capable desktop or laptop will often get better raw throughput.
- How do I tell if my ISP is throttling VPN traffic? Direct answer: Run identical tests with and without VPN and inspect traceroute; consistent slow VPN-only paths, or improvements after changing ports, suggest ISP shaping.
Summary: Diagnose first, change one thing at a time, prefer WireGuard, check MTU and DNS, and move the VPN to the router only when the router hardware supports the required throughput. If you complete the checklist and the issue remains, collect logs and open a provider support ticket with the exact test results. If you need whole-home routing instructions, follow this Mullvad and ProtonVPN router guide.
Internal resources for your next steps: compare alternatives in Mullvad vs Proton VPN, explore router setups in set up VPN router, or read the troubleshooting checklist in Fix VPN Speed Drops. For streaming or seedbox specific guidance see best VPN for streaming and Use VPN with a seedbox. If you need alternative provider comparisons refer to Mullvad vs NordVPN, ExpressVPN vs Mullvad, and ProtonVPN vs Mullvad.
External references: Mullvad pricing page and WireGuard documentation were consulted for provider features and protocol details.