Slow WiFi — Diagnose & Fix
Before changing anything, you need to figure out whether your WiFi is actually slow or your internet plan is slow. These are two completely different problems with different fixes. A WiFi issue means the wireless connection between your device and router is the bottleneck. An internet issue means your ISP connection is the bottleneck — and no amount of router tweaking will fix that.
Step 1: Measure Properly
Run two speed tests — one on WiFi, one on a wired ethernet connection to the same router:
| Test | Result | Diagnosis |
|---|---|---|
| Wired: 200 Mbps WiFi: 30 Mbps | Big gap | WiFi problem. Your internet is fine, but the wireless link is the bottleneck. Fix WiFi (below) |
| Wired: 25 Mbps WiFi: 22 Mbps | Similar speeds | ISP problem. WiFi is fine — you're getting what your plan provides. Upgrade your plan or call your ISP |
| Wired: 200 Mbps WiFi: 180 Mbps | Close enough | Normal. WiFi is always slightly slower than wired. This is fine |
Use fast.com (Netflix's speed test) or speedtest.net. Test multiple times — WiFi speeds fluctuate.
Step 2: WiFi Channel Congestion
In apartments and dense neighborhoods, the #1 cause of slow WiFi is channel congestion. Your router broadcasts on a specific channel. If your neighbors' routers are on the same channel, they interfere with each other. It's like everyone trying to talk at the same time in a crowded room.
2.4 GHz band
Has only 3 non-overlapping channels: 1, 6, and 11. If your router is on channel 3, it overlaps with both 1 and 6 — worse than just picking one of the three. Log into your router admin panel and set the 2.4 GHz channel manually to 1, 6, or 11 (whichever your neighbors aren't using).
5 GHz band
Has many more non-overlapping channels and much less congestion. If your router supports 5 GHz, always prefer it for speed. The tradeoff: 5 GHz has shorter range and doesn't penetrate walls as well as 2.4 GHz.
To scan for congestion, use a WiFi analyzer app on your phone (WiFi Analyzer for Android, AirPort Utility for iOS). These show which channels are crowded so you can pick a clear one.
Step 3: Router Placement
WiFi signals are radio waves. They get weaker with distance and get absorbed or reflected by obstacles. The rules are physics, not suggestions:
- Central location wins. A router in the corner of your house covers only half the space. Move it to a central location and coverage roughly doubles
- Elevation helps. WiFi signals radiate outward and slightly downward from the antennas. Placing the router on a shelf or high on a wall gives better coverage than on the floor
- Walls matter. Drywall reduces signal a little. Brick and concrete reduce it a lot. A single concrete wall can cut your speed by 50% or more
- Avoid these: Microwave ovens (interfere with 2.4 GHz), large metal objects (reflect signals), fish tanks (water absorbs WiFi), mirrors (metal backing reflects signals)
Step 4: Are You on the Right Band?
Most modern routers broadcast two networks — 2.4 GHz and 5 GHz. Some routers give them separate names (like "HomeWiFi" and "HomeWiFi-5G"), while others use the same name and let your device choose.
| Band | Speed | Range | Best For |
|---|---|---|---|
| 2.4 GHz | Slower (typically 50-100 Mbps) | Longer range, better through walls | IoT devices, far rooms, smart home |
| 5 GHz | Faster (300-800+ Mbps) | Shorter range | Streaming, gaming, video calls, close to router |
| 6 GHz (WiFi 6E/7) | Fastest (1+ Gbps) | Shortest range | High-bandwidth tasks, same room |
If your device is within 30 feet of the router with no thick walls in between, use 5 GHz. If you're far away or through multiple walls, 2.4 GHz will actually give better speeds despite being technically slower — because the connection is more stable.
Step 5: Check Connected Devices
Each device on your network shares the available bandwidth. If someone is downloading a large file, streaming 4K video, or a backup is running, it can slow everything else down. Log into your router to see what's connected:
- 192.168.1.1 — NETGEAR, Linksys, ASUS
- 192.168.0.1 — D-Link, TP-Link
- 10.0.0.1 — Xfinity
Look for devices you don't recognize (potential unauthorized users — see how to kick someone off your WiFi) and devices using heavy bandwidth.
Step 6: Update Router Firmware
Router manufacturers regularly release firmware updates that fix bugs, improve WiFi performance, and patch security vulnerabilities. Many people never update because it isn't automatic (on most routers). Log into your router's admin panel, find the firmware or update section, and check for updates. Some routers have a "Check for Updates" button; others require downloading a file from the manufacturer's website.
Step 7: Know When Your Router Is Too Old
WiFi standards have improved dramatically. If your router is more than 5-6 years old, upgrading may be the most impactful change:
| WiFi Standard | Year | Max Speed | Still Good? |
|---|---|---|---|
| WiFi 4 (802.11n) | 2009 | ~150 Mbps | Replace it — bottlenecking any modern internet plan |
| WiFi 5 (802.11ac) | 2014 | ~800 Mbps | Fine for most plans up to ~300 Mbps |
| WiFi 6 (802.11ax) | 2020 | ~1.2 Gbps | Great for most homes |
| WiFi 6E | 2021 | ~2.4 Gbps | Premium — adds 6 GHz band |
| WiFi 7 (802.11be) | 2024 | ~5+ Gbps | Overkill for now, but future-proof |
Step 8: Mesh WiFi for Large Homes
If your house is over 2,000 sq ft or has multiple floors, a single router probably can't cover everything. WiFi extenders (repeaters) are a cheap fix but they halve your speed because they use the same radio to receive and retransmit.
Mesh WiFi systems — Eero, Google/Nest WiFi, NETGEAR Orbi, ASUS ZenWiFi — use dedicated backhaul connections between nodes, maintaining full speed throughout your home. They're significantly better than extenders for large spaces.