Why Is My WiFi So Slow? 7 Common Causes (And How to Fix Them)

You’re paying for fast internet, so why is everything buffering? The frustrating truth I’ve found across hundreds of Geelong homes is that most slow-WiFi problems have nothing to do with your internet plan or your ISP. The problem is usually inside your home.

Here are the 7 most common reasons I see when helping people in Geelong, Surf Coast, and Bellarine — and how to fix each one.

Slow internet and slow WiFi feel identical. The fix is completely different. The first 90 seconds of the visit is sorting one from the other.

1. Your router is in the wrong spot

This is the #1 cause of slow WiFi I see in Australian homes.

The problem: WiFi signals radiate outward from your router. If it’s tucked in a cupboard, behind the TV, or in the corner of the house, half your signal is being wasted.

Signs it’s this:

• WiFi is fast near the router, slow in bedrooms
• You have “dead zones” in parts of the house
• Moving closer to the router fixes the problem

The fix:

• Move the router to a central, elevated location
• Keep it out of cupboards and off the floor
• Away from metal objects, mirrors, and fish tanks
• Not behind the TV (TVs block signal)

2. Too many devices on 2.4GHz

Your router broadcasts two WiFi networks: 2.4GHz and 5GHz.

The problem: 2.4GHz has better range but is much slower and gets congested easily. If all your devices are connecting to 2.4GHz, they’re fighting for bandwidth.

Signs it’s this:

• You have lots of smart home devices (they usually use 2.4GHz)
• Slow speeds even when you’re close to the router
• Your network name doesn’t indicate which band you’re on

The fix:

• Connect phones, laptops, and tablets to 5GHz when possible
• 5GHz is faster but shorter range — use it for devices near the router
• Keep 2.4GHz for smart home devices, printers, and devices far from the router
• Some routers let you create separate network names for each band

For the deeper why, see my 2.4GHz vs 5GHz explainer.

3. Neighbours’ WiFi interference

In Australia’s suburbs, houses are close together. If you can see your neighbours’ WiFi networks, they’re competing with yours.

The problem: WiFi uses shared radio channels. If everyone’s on the same channel, you’re all slowing each other down.

Signs it’s this:

• Slow WiFi in the evenings when neighbours are home
• You can see 10+ other networks from your house
• Problems started when new neighbours moved in

The fix:

• Log into your router and change the WiFi channel
• For 2.4GHz: Try channels 1, 6, or 11 (the only non-overlapping ones)
• For 5GHz: Try channel 36, 40, 44, 48, or higher
• Let your router auto-select if you’re not sure

4. Old router hardware

Routers age faster than you’d think. WiFi standards improve every few years, and older routers can’t keep up with modern devices.

The problem: A router 5+ years old may not support current WiFi standards, has weaker processors, and less memory.

Signs it’s this:

• Your router is from your original NBN installation
• You’ve never upgraded or replaced it
• Newer devices (recent iPhones, recent laptops) feel slower than older ones

The fix:

• If your router is 5+ years old, it’s time to upgrade
• Look for a WiFi 6 router — they handle multiple devices much better
• Don’t keep using an ISP-provided router if it’s old and tired
• Budget around $150–300 for a decent home router

5. Your house is too big for one router

This isn’t a criticism — Australian homes are often large, single-storey, and spread out. One router simply can’t cover 200+ square metres through multiple walls.

The problem: Physics. WiFi signal gets weaker with distance and loses strength passing through walls, especially brick and concrete.

Signs it’s this:

• Great WiFi in one part of the house, terrible in others
• The far end of the house is always slow
• You have thick walls or a split-level home

The fix:

• Consider a mesh WiFi system (multiple units that work together)
• Mesh systems are designed for coverage, not just speed
• Properly set up mesh — ideally with the units wired together using ethernet — beats range extenders every time
• See my mesh WiFi guide for honest pros and cons

6. Background devices hogging bandwidth

Modern homes have 20–40 connected devices. Many of them use bandwidth you don’t even notice.

The problem: Smart TVs, security cameras, backup software, and app updates all use bandwidth in the background.

Signs it’s this:

• Random slowdowns that come and go
• Slow speeds during business hours (work devices backing up)
• You have multiple streaming devices, cameras, or smart home gear

The fix:

• Check what’s connected to your network (your router admin page shows this)
• Pause or schedule cloud backups for overnight
• Reduce security camera quality settings if they’re cloud-based
• Consider QoS (Quality of Service) settings to prioritise important devices

7. Your internet plan is actually slow

Sometimes it really is the internet, not the WiFi.

The problem: You’re paying for a slow plan, or you’re not getting the speeds you’re paying for.

Signs it’s this:

• Slow speeds on wired AND wireless connections
• Slow at all times, not just in certain rooms
• You’re on an entry-level NBN plan (NBN 25 or Basic)

The fix:

• Run a speed test on a device plugged directly into the router via an ethernet cable
• Compare the result to what you’re paying for
• If wired is slow too, talk to your ISP — or read does your NBN provider actually matter?
• Consider upgrading your plan if it’s genuinely too slow for your household

Quick diagnosis checklist

Before calling anyone, try these:

1. Restart your router (unplug for 30 seconds, wait 2 minutes after plugging back in)
2. Test wired vs wireless (if wired is fast, it’s a WiFi problem)
3. Test close vs far (if close is fast, it’s a coverage problem)
4. Test different times (if evenings are slow, it’s congestion)
5. Test different devices (if one device is slow, it’s that device)

Still slow? Get a proper assessment

If you’ve tried everything and your WiFi is still frustrating, it might be time for a professional look. I help homeowners in Geelong, Surf Coast, and Bellarine sort out WiFi problems without the jargon.

Questions people ask

Common questions

Will a WiFi extender fix my slow WiFi?+

Maybe, but usually no. Cheap extenders repeat a weak signal using the same radio they receive on, so you get slightly better coverage but often half the speed. Mesh systems — ideally with the units wired together by ethernet — are far better for whole-home coverage.

Should I call my ISP about slow WiFi?+

Only if your wired connection is also slow. Plug a laptop straight into the router with an ethernet cable and test. If wired is fast but WiFi is slow, your ISP literally can't help — the issue is inside your home.

Do I need to upgrade my NBN plan?+

Not if only certain rooms are slow — that's a WiFi coverage problem, not an internet problem. Pay for a faster plan and you'll just get faster internet to the front of the house and the same dead zone out the back.

Is my router too old?+

If it's more than 5 years old, almost certainly. WiFi 6 routers handle the multi-device homes we all live in now far better than older WiFi 5 hardware. Even a mid-range modern router will feel quicker.

Why is WiFi slow only in the evenings?+

Two usual suspects: neighbour interference (everyone comes home and turns on devices, congesting the same channels) and ISP-side congestion at your local POI (7–11pm peak hours). Try changing your WiFi channel first; if it's still slow on a wired connection, it's the ISP.

Does the router need to be in the centre of the house?+

Yes, ideally. WiFi radiates outwards in all directions, so a router in the corner of the house wastes about half its signal on your front yard. Central, up high, out of cupboards is the rule.

Serving Geelong, Surf Coast, and Bellarine Peninsula.

Why Oh WiFi · 0489 998 445 · hello@whyohwifi.com.au