2.4 GHz or 5 GHz? Which band to use, and what band steering does
Most routers broadcast two bands, sometimes three, and choose for your devices. Knowing what each band is good at tells you when to let the router decide and when to step in.
In short
- 2.4 GHz reaches further and crosses walls better, but it's slower and crowded: only three channels that don't overlap. 5 GHz is faster and less crowded, with shorter range.
- Behind heavy walls the difference is large: in NIST's measurements brick costs about 6 dB at 2.4 GHz and 15 dB at 5 GHz.
- With one network name, band steering lets the router push capable devices toward 5 GHz. It works well most of the time; it chooses badly at the edges.
- Split the bands, at least temporarily, when a 2.4 GHz-only smart device won't pair, or when a far device keeps bouncing between bands.
On this page
Your router almost certainly broadcasts on two bands, 2.4 GHz and 5 GHz, and newer ones add 6 GHz. Often they share a single network name and the router decides which band each device uses. Most of the time that's fine. When a particular room or device misbehaves, understanding the bands is usually what unlocks it.
What each band is good at
2.4 GHz is the older band. Its strengths are range and penetration: it carries further and loses less through walls. Its weaknesses are speed and space. There are only three channels that don't overlap each other (1, 6 and 11), every neighbour's router uses one of them, and the band is shared with Bluetooth, many smart home gadgets, baby monitors and microwave ovens.
5 GHz has many more channels and far less competition, so it's faster and steadier where the signal is good. It fades sooner with distance and loses much more through walls and floors. In NIST's laboratory measurements, brick cost about 6 dB at 2.4 GHz and 15 dB at 5 GHz; 20 cm of reinforced concrete cost about 31 dB and 55 dB. Every 3 dB halves the signal, so behind heavy walls 5 GHz runs out first. See what blocks Wi-Fi at home for the full figures.
Some 5 GHz channels are shared with weather and other radar. Routers using them must listen first and move away if they detect radar, which is why a 5 GHz network can occasionally take a minute to appear after a restart.
6 GHz, used by Wi-Fi 6E and Wi-Fi 7, has the most room of all but even shorter reach, and only recent devices can use it. It's excellent in the same room as the router or the next one, rarely further.
Which band for which device
In rooms near the router, 5 GHz is almost always better for phones, laptops, TVs and consoles: more speed and less waiting for the air.
In far rooms, behind thick walls or on another floor, 2.4 GHz may be the steadier choice, even though it's slower. A stable 20 Mbps beats a 5 GHz link that keeps dropping. The signal reading tells you: on an iPhone, AirPort Utility's Wi-Fi scanner lists both bands of your network with their signal, so you can see how much each one has left in that room. How to check Wi-Fi signal strength on iPhone explains how.
Smart home devices, like plugs, bulbs, cameras and robot vacuums, often support only 2.4 GHz. That's normal and nothing to fix; it's also part of why 2.4 GHz is so crowded.
What band steering does
When both bands share one name, something has to decide which one each device joins. That's band steering, sometimes called smart connect. A router can't force a device onto a band; the device makes the final choice. What the router can do is make one band more attractive, for example by answering a dual-band device's first requests only on 5 GHz, or by suggesting a better band through standard messages that modern devices understand.
It works well for most homes: phones and laptops end up on 5 GHz near the router and on 2.4 GHz in the far corners, without anyone touching a setting.
It chooses badly in two situations. At the edge of coverage, a device can be nudged toward a 5 GHz link that's too weak and then fall back, so the connection works, stalls and recovers in a loop. And during setup, many 2.4 GHz-only smart devices get confused by a network that answers on two bands and fail to pair.
When to split the bands
You can usually give the two bands different names in the router's settings, for example Home and Home-5G. Then each device stays on the band you choose.
It's worth doing in two cases:
- A smart device won't pair. Split the bands, connect the device to the 2.4 GHz name, then merge them again if you prefer one name. The device keeps working afterwards.
- One device in a far room keeps flickering. Connecting it to the 2.4 GHz name only gives it the steadier link, at the cost of some speed.
The downside of separate names is that phones and laptops don't move between them on their own: a phone joined to the 5 GHz name will hold on to it in the garden rather than switch to 2.4 GHz. That's why one name with band steering is the better default, and split names are a tool for specific devices.
If a far room flickers no matter which band you choose, the band isn't the problem: the room needs better coverage. Wi-Fi not reaching one room goes through the options.