The difference between 2.4 GHz and 5 GHz WiFi

If your WiFi router is showing two network names, one usually has “2.4G” in it and the other “5G.” Most people just pick one and wonder why some devices run slow or drop out. Here’s what’s actually going on and which one to use.

What Do 2.4 GHz and 5 GHz Mean?

GHz stands for gigahertz. It’s the radio frequency your router uses to send and receive data wirelessly. 2.4 GHz and 5 GHz are two different radio bands. Same router, different frequencies, different behaviour.

Most modern routers are dual-band, meaning they broadcast both at the same time. Some newer routers are tri-band and add a second 5 GHz band or a 6 GHz band, but that’s a separate topic.

2.4 GHz WiFi

Range: Good. 2.4 GHz travels further and gets through walls, floors and double brick better than 5 GHz.

Speed: Slower. Maximum theoretical speed on 2.4 GHz using 802.11n is around 300 Mbps. Real world speeds are much lower, often 50 to 100 Mbps at best depending on distance and interference.

Interference: Bad. 2.4 GHz shares the same frequency range as microwave ovens, baby monitors, Bluetooth devices and every neighbour’s router. In a unit block or suburban street with twenty networks all sitting on 2.4 GHz, congestion is a real problem.

Channels: 2.4 GHz has 13 channels available in Australia but only three are non-overlapping: channels 1, 6 and 11. Every other channel bleeds into the ones next to it. Most routers default to auto channel selection, which often picks a congested one.

Best for: Devices that are far from the router. Smart home devices like Philips Hue, older IoT sensors, smart plugs. Devices that don’t need fast speeds but need to stay connected across a large house.

5 GHz WiFi

Range: Shorter. 5 GHz doesn’t travel as far as 2.4 GHz and struggles with thick walls. Double brick cuts it significantly. The signal drops off faster with distance.

Speed: Much faster. 802.11ac (WiFi 5) on 5 GHz delivers real world speeds of 400 to 800 Mbps on a good connection. 802.11ax (WiFi 6) pushes higher again. For NBN connections running at 100 Mbps, 250 Mbps or 1 Gbps, 5 GHz is where you want to be.

Interference: Much less. 5 GHz has 24 non-overlapping channels available in Australia. Far less congestion. Less competition from neighbouring networks and household devices.

Channels: Common 5 GHz channels used in Australia include 36, 40, 44, 48, 149, 153, 157 and 161. Wider channel widths, 80 MHz or 160 MHz, give higher throughput but can cause their own interference in dense environments.

Best for: Anything close to the router that needs speed. Laptops, phones, smart TVs streaming 4K, gaming consoles, desktop computers with a WiFi card. Any device where a fast, stable connection matters.

Side by Side

Which One Should You Use?

For most devices that are reasonably close to the router, use 5 GHz. It’s faster and less congested. For devices that are far away, behind thick walls or in another part of the house, use 2.4 GHz.

Smart TVs in the same room as the router, use 5 GHz. Smart plug in the garage three rooms away, use 2.4 GHz.

Some routers have band steering turned on, which automatically pushes devices to the faster band. This works well on some routers and creates connection problems on others, particularly with older smart home devices that only support 2.4 GHz. If a device won’t connect, turn off band steering and set up the two bands as separate networks with different names so you can choose manually.

Why Your WiFi Drops Out on 5 GHz Near Walls

5 GHz signals are absorbed by building materials more easily than 2.4 GHz. Concrete, double brick and plasterboard with foil insulation all attenuate 5 GHz significantly. A device showing full bars of 5 GHz signal in the same room as the router can drop to one bar two rooms away with a brick wall in between.

If 5 GHz keeps dropping out in certain areas of your home, the answer isn’t to switch everything to 2.4 GHz. The answer is a wireless mesh system or a wired access point in the area where coverage is poor. A wireless extender running on 5 GHz half a house away from the router is rarely the right solution.

What About WiFi 6 and 6 GHz?

WiFi 6 (802.11ax) works on both 2.4 GHz and 5 GHz bands and improves performance in congested environments through a technology called OFDMA, which allows the router to communicate with multiple devices at the same time more efficiently.

WiFi 6E adds a 6 GHz band. More channels, less congestion, even faster speeds. The catch is range. 6 GHz drops off faster than 5 GHz. It’s really only effective in the same room or the next room with clear line of sight.

For most Melbourne homes on standard NBN plans, a WiFi 6 router on the 5 GHz band is more than sufficient. WiFi 6E is useful in high density environments or large homes with multiple access points.

Case Study: 5 GHz Dropouts in a Brighton Double-Brick Extension

A client in Brighton contacted us because their Zoom calls kept dropping out in their newly built rear home office. They had a Netgear NightHawk X6 R8000 modem located in the front hallway. The client had already spent $400 on a high-end “Wi-Fi Extender” from a local retailer, plugged it into the office wall, and the dropouts actually got worse.

We ran a Wi-Fi spectrum analysis on site. The front of the house was original 1930s construction, but the rear office was a modern extension separated from the main house by what used to be the exterior double-brick wall.

Here is what was happening: The router had “Band Steering” turned on, broadcasting one network name. The laptop in the office would connect to the 2.4 GHz band, which easily penetrated the brick wall, but was so heavily congested by neighbouring networks that the speeds were too slow for HD video calls. The router would then aggressively try to “steer” the laptop to the faster 5 GHz band. However, the 5 GHz signal was completely absorbed by the dense double-brick wall. The laptop would connect, immediately lose the signal, and drop the call.

The expensive Wi-Fi extender the client bought was failing for the same reason—you cannot “extend” a 5 GHz signal that has already been killed by a brick wall. A wireless mesh system would have suffered the exact same fate because the wireless “backhaul” between the nodes cannot penetrate dense masonry.

The Fix: You cannot beat physics with more expensive Wi-Fi antennas; you beat it with copper. We ran a single, concealed Cat6 Ethernet cable through the roof cavity from the front modem directly into the rear office. We ceiling-mounted a dedicated, hardwired Wi-Fi 6 Access Point (a TP-Link Omada) in the office and disabled the aggressive band steering on the main modem.

The client went from dropping three calls a day to a rock-solid 400 Mbps connection in the office. They returned the $400 extender, and our permanent, hardwired solution ended up costing them less than buying the premium wireless mesh system they had been considering.

When to Call a WiFi Technician

If you’ve tried switching bands and the drop-outs keep happening, the issue usually isn’t which band you’re on. It’s more likely a faulty modem, an NBN fault, poor router placement, interference from a neighbouring network or a coverage problem that needs a proper wireless assessment.

Computer Technicians carries wireless diagnostic tools and does full WiFi audits for Melbourne homes and businesses. We measure signal strength room by room, check for channel congestion, test the NBN connection and identify exactly what’s causing the problem.

Give us a call on 0484 357 559 or email info@computertechnicians.com.au.

Common Questions We Get About This

My laptop shows 5 GHz but internet feels slow. Why? Signal strength and actual throughput are different things. A device can show strong 5 GHz signal but still have poor throughput if there’s channel congestion, interference from a neighbouring network on the same channel, or a driver issue on the WiFi adapter. Run a speed test with a cable first to rule out the NBN connection itself.

Should I name my 2.4 GHz and 5 GHz networks differently? Yes, if your router lets you. Giving them different SSIDs means you can manually choose which band each device connects to. Useful for smart home devices that only support 2.4 GHz and keep failing to connect when band steering pushes them to 5 GHz.

My router only shows one WiFi network. Does it have both bands? Probably yes. Most modern routers with a single SSID are using band steering to manage both bands automatically. Check the router admin panel, usually at 192.168.1.1 or 192.168.0.1, to see the band configuration and whether band steering is enabled.

My SONOS keeps dropping out. Is this a 2.4 vs 5 GHz issue? SONOS devices use 2.4 GHz or SonosNet, their own mesh protocol. The most common cause of SONOS drop-outs is WiFi channel congestion on 2.4 GHz or a router that’s too aggressive with band steering. Fixing the 2.4 GHz channel selection on the router usually resolves it.

Can 5 GHz go through floors? Partially. A single timber floor with standard insulation, yes, with some signal loss. Concrete floors, significantly less. Double brick between floors, expect a major drop. If 5 GHz can’t reach a floor reliably, a wired access point or powerline adapter with a WiFi access point is the better fix.