Why Does Speed Test Differently on Different Devices?
Run a speed test on your phone, then on your laptop, then on your smart TV — all on the same WiFi network — and you’ll likely see different numbers for all three. This is expected and normal, not a sign that something is broken. Test your devices individually at instantspeedtest.net/ and compare the results.
Why Different Devices Show Different Speeds
| Variable | Effect on Speed Test Result |
|---|---|
| WiFi adapter generation (WiFi 4/5/6) | Older adapters cap out at lower speeds |
| WiFi band (2.4 GHz vs 5 GHz) | 5 GHz can be 2–5x faster at close range |
| Number of antennas (1×1, 2×2, 4×4) | More antennas = higher maximum speed |
| CPU speed of device | Faster CPUs process network data faster |
| Background processes | Active sync/updates consume bandwidth |
| Distance from router | Greater distance = weaker signal = lower speed |
| Browser version / speed test app | Different implementations measure differently |
| Device thermals | Hot devices throttle processing, including network |
The Most Meaningful Speed Test — Which Device to Use
To measure your internet plan’s true capability, test on a device directly connected via Ethernet — this eliminates WiFi variability entirely and shows what your ISP delivers to your modem/router. To test your WiFi capability for a specific device, test on that device in its typical location. For example, if your laptop is slow while gaming in the bedroom, test the laptop from the bedroom — that’s the real number that matters for that use case. Don’t test your phone in the same room as the router and conclude that your bedroom has good WiFi.
Related Guides
- WiFi Slow on Laptop But Fast on Phone
- Internet Slow Only on One Device
- Wired vs Wireless Internet Speed
- How to Test Internet Speed Without App
- Ookla vs Fast.com vs Google Speed Test
- How to Test Mobile Data Speed
Frequently Asked Questions
Which device gives the most accurate speed test?
A device connected via Ethernet to your router gives the most accurate view of your internet connection speed. Among WiFi devices, a modern laptop or phone with WiFi 6 on a 5 GHz band close to the router will come closest to your true connection speed. The highest result you get across devices generally reflects your internet plan’s actual delivered speed.
Why does my old phone show much lower speeds than my new phone?
Older phones may have WiFi 4 or early WiFi 5 adapters with fewer antennas than newer models. A 2018 phone with a 1×1 WiFi 5 adapter caps at ~300 Mbps theoretically vs a 2024 phone with a 2×2 WiFi 6E adapter reaching 1.5+ Gbps theoretically. Real-world speed differences between a 2018 and 2024 phone on WiFi can easily be 3–5x on the same network.
My desktop is faster via WiFi than my laptop — why?
Desktop WiFi adapters (PCIe cards with external antennas) are typically higher-performance than laptop’s thin-and-light internal adapters. A desktop PCIe WiFi 6 card with three antennas in a 3×3 MIMO configuration massively outperforms a laptop’s compact 1×1 or 2×2 internal adapter. Desktop placement also tends to provide better line-of-sight to routers than laptops sitting on desks below router height.