When you run an internet speed test, you are measuring the speed between your home and your provider’s servers on the internet. But there is another kind of speed that matters just as much: how fast devices inside your house can talk to each other. That internal speed — your local network speed — decides how quickly files move from your laptop to a NAS drive, how smoothly a 4K movie streams from your media server to the TV, and how responsive a network printer feels.
The good news is that testing your home network speed between devices is free, takes only a few minutes, and tells you whether your Wi-Fi, your cables, or a particular device is the bottleneck. In this guide we will cover the simplest browser-based method, dedicated tools for Windows, Mac, Android, and iPhone, and how to read the results like a network technician.
Why Local Network Speed Is Different from Internet Speed
Your internet plan might be 300 Mbps, but your home network can be much faster than that. A modern Wi-Fi 6 laptop copying a file to a wired PC can move data at 600–900 Mbps because the traffic never leaves your house. Conversely, a laptop on a weak Wi-Fi signal in a far bedroom might manage only 20 Mbps to the router — which is why a big file transfer crawls even though Netflix works fine. Testing device-to-device speed isolates the local half of the equation, so you can fix the right thing.
Method 1: The Quick File Copy Test
Step 1: Pick Two Devices and a Test File
Choose the two devices you care about — for example, your laptop and a desktop PC or NAS. Prepare a single large test file of 1–2 GB (a video file works perfectly) so the transfer runs long enough to stabilise.
Step 2: Share and Copy
On Windows, right-click the folder containing the file, choose Properties, then Sharing, and share it on your private network. From the second device, open the shared folder over the network and copy the file across while watching the transfer speed shown in the copy dialog.
Step 3: Convert and Compare
Windows shows speed in MB/s (megabytes). Multiply by 8 to get Mbps: 50 MB/s equals about 400 Mbps. Repeat the test with one device plugged into Ethernet to see how much the Wi-Fi hop is costing you.
Method 2: iPerf3 — The Technician’s Standard Tool
Step 1: Install iPerf3 on Both Devices
iPerf3 is a free, open-source tool available for Windows, macOS, Linux, Android, and iOS. Download it only from the official iPerf project download page or your platform’s app store to avoid bundled junk.
Step 2: Start the Server on One Device
On the device that will receive the test (ideally the one wired to the router), open a terminal or Command Prompt and run iperf3 -s. It will wait quietly for a connection.
Step 3: Run the Client Test
On the second device, run iperf3 -c 192.168.1.50, replacing the address with the server device’s local IP. For a more realistic result, add -P 4 to run four parallel streams and -R to test the reverse direction. The summary line shows your true local throughput in Mbps or Gbps.
Method 3: LAN Speed Test Apps
If command lines are not your thing, apps such as LAN Speed Test (Windows/Mac) or Wi-Fi Speed Test apps on Android automate the same idea with friendly graphs. Some routers also include a built-in speed test in their admin page or companion app, though most of those measure the internet connection rather than device-to-device traffic — check the wording carefully. For general tuning help once you know your numbers, the step-by-step walkthroughs in Network Ustad’s home networking how-to library cover everything from channel selection to QoS.
What Results Should You Expect?
Use these rough benchmarks. A wired gigabit Ethernet connection should deliver 900–950 Mbps. Wi-Fi 6 on 5GHz with a strong signal typically achieves 500–800 Mbps. Wi-Fi 5 usually lands between 200 and 450 Mbps. The 2.4GHz band often manages only 50–150 Mbps, and a weak signal can drag any of these down to a fraction of their potential. If your numbers are far below the benchmark for your hardware, the problem is usually signal strength, interference, an old 100 Mbps switch or cable in the chain, or a device negotiating a slower link than you expect.
How to Run a Meaningful Test
Test One Variable at a Time
Test the same two devices first both wired, then one on Wi-Fi, then both on Wi-Fi. Note the distance and walls between the device and router for each run. This methodical approach tells you exactly which hop is slow.
Repeat and Average
Wi-Fi speeds fluctuate second by second. Run each test three times and use the middle result. Avoid testing while someone is streaming or downloading updates in the background, as that traffic competes with yours.
Check the Link Speed Too
On Windows, open Settings, Network & Internet, then your adapter’s properties to see the negotiated link speed. On many routers, the client list shows each device’s connection rate. A laptop linked at 72 Mbps on 2.4GHz will never test faster than that, no matter how good the router is.
Interpreting Your Results: Three Example Scenarios
Numbers mean little without a story, so here are three typical outcomes and what to do about each. Scenario one: your wired PC and NAS transfer at 940 Mbps, but your laptop manages only 85 Mbps in the office — your infrastructure is perfect and the laptop’s Wi-Fi link is the entire problem; move the router, add an access point near the office, or cable the desk. Scenario two: everything, including two wired devices, tops out around 95 Mbps — something in the chain is an old 100 Mbps device: a legacy switch, a tired cable, or a router LAN port specification. Swap components one at a time until the ceiling lifts. Scenario three: speeds swing wildly between runs (50, then 700, then 120 Mbps) — that pattern screams interference or a neighbour’s network on your channel; test again on the other band and after changing channels. Each pattern points at a different fix, which is exactly why measuring beats guessing.
Common Mistakes and Tips
The most common mistake is confusing MB/s with Mbps and concluding the network is eight times slower than it really is. Second, testing between two devices that are both on weak Wi-Fi and blaming the router, when placement is the real issue. Third, forgetting that a single slow device — an old network printer or a cheap USB adapter — only limits its own transfers, not the whole network. Finally, remember to test after every change: moving the router two metres can double a bedroom’s throughput.
Conclusion
Testing your home network speed between devices separates the two halves of every slowdown: your internet connection and your local network. With a simple file copy or a free iPerf3 test, you can measure the local half in minutes, compare it against realistic benchmarks, and fix the actual bottleneck instead of guessing. Once you know your numbers, every other upgrade decision — new router, mesh kit, or a simple cable — becomes much easier.
Frequently Asked Questions
Can I test local network speed without installing anything?
Yes. A large file copy between two devices using a shared folder shows live transfer speeds with no extra software. It is less precise than iPerf3 but perfectly fine for spotting bottlenecks.
What is a good LAN speed between two computers?
On gigabit Ethernet, expect 900 Mbps or more. On Wi-Fi 6, 500–800 Mbps near the router is healthy. Anything far below your hardware’s capability suggests a signal, cable, or settings problem.
Why is my local transfer slower than my internet speed?
Usually because one device has a weak Wi-Fi signal, an old Wi-Fi standard, or a 100 Mbps Ethernet port or cable somewhere in the path. The slowest link in the chain sets the ceiling.
Does iPerf3 work between a phone and a PC?
Yes. Install an iPerf3-compatible app on the phone and the program on the PC, run one as server and the other as client, and you can test your phone’s real Wi-Fi throughput.
Should I test with the server device wired or wireless?
Wired is best. Plugging the server into the router with Ethernet removes one Wi-Fi hop, so the result reflects only the wireless device’s connection quality.
Leave a Reply