Why Is My nbn Slow at Night? Real Causes and Fixes | MATE

Home & Business Internet Blog | MATE | 14 October 2026

Why your nbn slows down at night, and what you can actually do about it

It’s 8pm. You’ve finally sat down to watch something, and the little loading wheel shows up again. Sound familiar?

For years, the answer was simple: everyone was online at once and the network couldn’t keep up. In 2026, that’s no longer the usual story. Here’s what’s really going on, how to work out the cause in five minutes, and the fixes that actually work.

The short answer

Peak-hour congestion on the nbn has largely been engineered out. The ACCC’s final broadband report found fixed-line services delivering 99.4% of plan speed in the busy evening hours. So if your internet slows down at night, the cause is most often WiFi interference, too many active devices, or a line technology that can’t sustain your plan speed.

What used to cause it, and what changed

Until recently, nbn charged internet providers for the bandwidth they used through a fee called CVC (Connectivity Virtual Circuit). Providers had to decide how much capacity to buy, and when they didn’t buy enough, everyone’s speeds dropped during the busy evening hours. That’s where the nbn’s reputation for slow nights came from.

That model is gone. nbn removed CVC charges for plans of 100Mbps and above in December 2023, and for the remaining fixed-line and fixed wireless tiers from 1 July 2026. Bandwidth is now included in a flat wholesale price, so providers no longer have the same cost pressure to ration it at peak times.

The results show it. When the ACCC started measuring broadband performance in 2017, average busy-hour speeds were around 80 to 85% of plan speeds. In its final Measuring Broadband Australia report in June 2026, fixed-line services were averaging 99.4% of plan speed during the peak evening period, and the share of underperforming services had dropped from 13.9% in 2018 to 5.6%.

Diagnose it in five minutes

Before you change anything, find out where the slowdown is actually happening. All you need is a laptop, an Ethernet cable and a speed test website or app. Run each test at night, when the problem shows up.

1. Test wired, next to your router. Plug your laptop straight into your modem/router with an Ethernet cable and run a speed test. This shows what your nbn connection is delivering, with WiFi taken out of the picture.
2. Test on WiFi, in the same room. Unplug the cable and run the same test over WiFi, standing near the router. This shows how much speed your router’s WiFi is losing.
3. Test on WiFi, in the problem room. Move to the room where things are slowest, like the bedroom or back lounge, and test again. This shows how much your WiFi signal drops with distance and walls.
4. Test again at a quiet time. Repeat the wired test at a quiet time, like mid-morning on a weekday. This shows whether the evening itself is making a difference.

What your results tell you:

• Wired is close to your plan speed at night: your nbn connection is fine. The problem is inside your home.
• Wired is fine, but WiFi near the router is much slower: your router is the bottleneck. It may be old, or set up poorly.
• WiFi is fine near the router but poor in the problem room: it’s a coverage issue. Moving the router, or adding mesh WiFi, is the fix.
• Wired is well below your plan speed at night, but fine at a quiet time: this points to a genuine network or provider issue. Skip to the last section.
• Wired is well below your plan speed at all times: this is often your line itself, especially on Fibre to the Node (FTTN).

For a more detailed walkthrough, see our guide to running an nbn speed test with a direct connection.

The seven real causes, in order of likelihood

1. WiFi congestion in busy neighbourhoods

In apartments and dense suburbs, dozens of neighbouring WiFi networks share the same airwaves, and they’re all busiest in the evening. If your router is stuck on a crowded band or channel, your WiFi slows down even though your nbn connection is fine.

2. An ageing router

A router from 2018 was built for the plans of 2018. Older routers may not support newer WiFi standards, can struggle with lots of devices, and may not deliver the full speed of a faster plan over WiFi. If you’re moving to fibre, read do you need a new modem when you upgrade to fibre?

3. Too many devices at once

Evenings are when everyone’s home. TVs stream, consoles download updates, and phones back up photos the moment they’re plugged in to charge. Every device takes a share of your WiFi airtime and your bandwidth. If this sounds like your place, our guide to sharing internet across a big household covers the fixes.

4. Upload saturation

Most plans have far less upload than download. When someone is on a video call, uploading files or backing up to the cloud, the upload can max out. When that happens, everything else on the connection feels sluggish, even browsing and streaming.

5. FTTN line quality and distance from the node

On Fibre to the Node, the last stretch to your home runs over copper. The further you are from the node, and the older or wetter the copper, the less speed it can carry. This tends to show up as instability or dropouts rather than a clean speed drop.

6. The wrong speed tier for your household

If your wired speed test is hitting your plan’s maximum every night and the household still runs out of room, you may simply have outgrown your plan. That’s a genuine reason to upgrade, but it’s further down the list than most people expect.

7. A genuine provider or network issue

It does still happen, through local faults, outages or a problem with your connection. But it’s now the least likely cause, not the first.

What typical evening speed actually means

When you compare nbn plans, you’ll see a “typical evening speed” next to each one. It’s the average download speed customers on that plan get between 7pm and 11pm, the busiest time of the day. It’s a useful guide, but it’s an average, not a guarantee. Your own result depends on your connection type, your equipment and your home setup.

Here’s how MATE’s typical evening speeds compare to each plan’s maximum:

Correct as at 14 October 2026.

To be upfront: on fixed-line connections, evening speeds sit very close to the plan maximum. On fixed wireless, they can sit well below the headline number, because the connection relies on a shared radio signal from a tower. If you’re on fixed wireless, use the typical evening speed, not the plan name, to judge what to expect. You can see all of MATE’s nbn plans and typical evening speeds here.

Fixes that work, ranked by cost

Free

• Restart your modem/router. Switch it off at the wall for 30 seconds. It clears its memory and can sort out sluggish speeds.
• Use the right WiFi band. Put devices close to the router on 5GHz, which is faster and less crowded. Many routers do this automatically with a feature called band steering.
• Change your WiFi channel. In apartments and busy suburbs, a free WiFi analyser app shows which channels are crowded so you can pick a quieter one.
• Move your router. Central, up high and out in the open works best. Keep it away from microwaves, fish tanks and mirrors.
• Plug in what doesn’t move. Connect the TV, console and work computer with Ethernet cables. If you have mesh WiFi, wiring the units to each other (wired backhaul) helps too.
• Schedule big downloads overnight. Set game updates and cloud backups to run while you sleep.

Our setup guides walk you through your modem’s settings.

Low cost

• A newer router. If your router is several years old, a WiFi 6 or WiFi 7 model can make a big difference.
• Mesh WiFi. If you’ve got dead spots in several rooms or a double-storey home, mesh spreads the signal more evenly.

Plan change

Change your speed tier. Only worth it if your wired speed test is already hitting your current plan’s limit. MATE has no lock-in contracts and no plan change fees, so you can move up (or back down) if your results point that way.

Technology change

Upgrade to full fibre. If you’re on FTTN and your wired speeds are poor at all times, the copper line is likely the limit. A fibre upgrade replaces it entirely. Check whether your address can upgrade, or find out more about nbn connection types.

When it really is your provider

If your wired speed test is well below your plan’s typical evening speed, night after night, it’s time to get in touch. To help us sort it quickly, gather:

• screenshots of several wired speed tests, with the date and time
• results from a quiet time of day for comparison
• when the problem started, and whether it happens every night or only sometimes
• any dropouts, and roughly when they happen.

When you contact MATE’s Australian-based support team, we’ll check your connection, look for faults or outages in your area, and help you work out the next step. 

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