How to Fix Slow WiFi on One Device Only — 8 Targeted Fixes
When all other devices have fast WiFi but one device is slow, the issue is almost certainly in the device itself — not the router or ISP. Test the slow device at instantspeedtest.net/ and compare results to a working device on the same WiFi.
Single-Device Slow WiFi Causes — By Device Type
| Device Type | Most Common Cause | Fix |
|---|---|---|
| Windows laptop/PC | WiFi adapter driver outdated or throttled | Update driver; disable power management |
| Windows laptop/PC | Connected to 2.4 GHz while 5 GHz available | Forget 2.4 GHz SSID; force 5 GHz connection |
| MacBook | WiFi channel congestion (auto-selects busy channel) | Router: manually assign WiFi channel 36/40/44 (5 GHz) |
| iPhone/Android | Background apps consuming bandwidth | Force close all background apps; check data usage |
| Smart TV | Old firmware; 2.4 GHz only radio | Update firmware; use Ethernet if TV supports it |
| Gaming console | Console in WiFi dead zone | Add mesh node; use Ethernet |
| Any device | Too far from router / inside cabinet | Reposition device; ensure line of sight |
| Any device | Malware consuming bandwidth (PC) | Run malware scan; check Task Manager network tab |
The 2.4 GHz vs 5 GHz Band Problem — Single Device Cause
The most common cause of one device being slower than others: it’s connected to the 2.4 GHz band while other devices use 5 GHz. 2.4 GHz maximum real-world speed is 50–150 Mbps; 5 GHz delivers 300–600 Mbps at close range. Windows computers often stubbornly stick to 2.4 GHz once they’ve learned that SSID. Fix: go to Network Settings → WiFi → your network → Forget → reconnect by selecting specifically the 5 GHz SSID (if your router has separate SSIDs) or ensure band steering is enabled in the router to automatically assign 5 GHz to capable devices. See our 2.4 GHz vs 5 GHz guide.
Related Guides
- 2.4 GHz vs 5 GHz WiFi
- Wired vs Wireless Speed
- Fix WiFi Disconnecting
- Fix WiFi Not Connecting to 5 GHz
- Download Speed Slower Than Plan
- Fix Slow Internet Windows 11
Frequently Asked Questions
How do I check which WiFi band my device is connected to?
Windows: click WiFi icon in taskbar → your network → Properties → shows frequency band (2.4 GHz or 5 GHz). Android: Settings → WiFi → your network → shows frequency. iPhone: go to Settings → WiFi → tap the (i) next to your network — shows no frequency info directly, but if you have separate SSIDs for 2.4 and 5 GHz, the connected SSID tells you the band. Mac: hold Option key → click WiFi icon → shows connected frequency and channel.
Why does one device get lower speeds than others on the same 5 GHz?
If already confirmed on 5 GHz but still slower: WiFi adapter quality varies significantly between devices. A budget laptop’s 802.11ac 1×1 MIMO antenna achieves 150–200 Mbps maximum; a premium laptop’s 4×4 MIMO achieves 600+ Mbps at the same distance. The number of spatial streams (1×1, 2×2, 4×4) determines maximum WiFi speed per device independent of router quality. Check your device’s WiFi adapter specifications for MIMO stream count.