Why Is My NBN So Slow? Real Causes and Fixes That Actually Work

First: what speed are you actually getting?

Before you blame the NBN or call your provider, you need to know what your line is actually delivering. Not what your phone reckons over Wi-Fi from the back bedroom. The actual speed at the modem.

Most "slow NBN" complaints we see come from speed tests done over Wi-Fi from a phone, which tells you next to nothing about whether the NBN line itself is healthy.

How to run a proper speed test

Use Ookla Speedtest at speedtest.net, on a computer, plugged directly into the modem with an Ethernet cable. Run the test three times during the day and three times in the evening between 7 and 11 pm.

Make sure nothing else is downloading or streaming while you test. Close cloud backups, pause torrents, and get the kids off the Xbox.

Compare your result to your plan's "typical evening speed", which is the number your provider quotes on the bill, not the headline plan speed. If you're consistently below that during evenings, you've got a real problem worth chasing.

Wired vs Wi-Fi test (the bit nobody does)

Run the same test once on Ethernet, once on Wi-Fi from the same room as the modem.

If the Ethernet test hits the plan speed but Wi-Fi is far below, your NBN line is fine. Your Wi-Fi is the problem. If both are equally slow, the issue is upstream of your home network.

This single comparison saves more wasted ISP support calls than anything else we tell customers. Most "slow NBN" complaints we see turn out to be Wi-Fi issues, not NBN issues.

What your plan speed actually means in 2026

If you haven't checked your plan in the last six months, your speed might have changed without you noticing. NBN Co dropped new speed tiers in September 2025 and most major providers automatically migrated existing customers up.

If you were on a 100/20 plan, you're probably now on 500/50. 250/25 plans went up to 750/50, and the top end went up to roughly 1Gbps.

This matters because the gear in your house may not be able to deliver the new speed. We'll come back to that in the home setup section.

Is it the NBN, your provider, or your home?

Slow internet has three potential bottlenecks. The NBN line itself, your retail provider's wholesale capacity, or something in your home (modem, Wi-Fi, devices).

Each of these is a different fix path, which is why generic "restart your router" advice fails so often. You need to know where the slowness actually lives before you can sort it.

The wired-vs-wireless test from the previous section is the first divider. If wired is slow, the issue is in the NBN or your provider. If wired is fine but wireless is slow, the issue is in your home.

From there, time of day matters. If wired speeds are fine in the morning and crash at 8 pm, you're looking at peak-hour congestion at your provider. If wired speeds are bad all day, it's likely the NBN line, your connection type, or hardware.

Slow because of your NBN connection type

Your NBN technology type sets a hard ceiling on what's possible. No modem, no router, no plan upgrade can push past what the line itself can deliver.

There are five types in active use. The one you have changes everything about what's worth doing next.

FTTN: the copper line problem

Fibre to the Node uses NBN fibre to a green cabinet in your street, then the existing copper phone line for the last leg into your house. Copper has hard physical limits, and those limits get worse the further you are from the node.

The ACCC's data on this is clear. A 100 Mbps FTTN plan delivers an average of 88.2 Mbps in real-world testing, compared to 104.4 Mbps on FTTP and HFC plans of the same tier. On 50 Mbps plans, FTTN sits at 47.6 Mbps versus 52 plus on the fibre and HFC alternatives.

If you're at the far end of your street's copper run, you might never have hit the speed your plan advertises. NBN Co confirms what speed a line can actually achieve after connection, but they only tell you when you ask, and most people don't.

FTTC: similar limits, but a free upgrade is coming

Fibre to the Curb runs fibre most of the way, then uses a much shorter run of copper from a small node in the gutter outside your house. Speeds are usually better than FTTN but still capped at roughly 100 Mbps maximum.

NBN Co has flagged FTTC for accelerated retirement. From July 2026, around 600,000 FTTC homes become eligible for free FTTP upgrades without needing to order a high-speed plan first.

If you're on FTTC and your speeds are inconsistent, the proper fix for 2026 is the upgrade, not chasing your provider for an extra few Mbps.

FTTP and HFC: when slow isn't usually the line

Fibre to the Premises runs fibre all the way to a small white NBN box on the wall inside your house. Hybrid Fibre Coaxial uses the old Foxtel cable network with NBN equipment. Both deliver the full advertised plan speed in normal conditions.

If you're on FTTP or HFC and your speeds are slow, the line is rarely the issue. The bottleneck is almost always the modem, the Wi-Fi, or peak-hour congestion at your provider.

This is the bit most customers get wrong. They assume "the NBN is slow" when their FTTP line is delivering 940 Mbps and their old WiFi 5 modem is bottlenecking it at 200.

Fixed wireless and Sky Muster

Country properties without fibre or copper get either Fixed Wireless (a dish on the roof pointing at an NBN tower) or Sky Muster (a satellite service for the most remote properties).

Both are more variable than fixed-line connections. Fixed Wireless speeds depend on tower distance, weather, and how busy your tower is. Sky Muster has high latency that affects video calls and gaming regardless of how fast it tests.

If you're on either of these, your benchmark for "normal" should be lower than what city customers get. NBN Co has been progressively upgrading fixed wireless towers to deliver better peak speeds, but tower congestion is still the most common issue.

The free fibre upgrade you might not know about

This is the biggest thing most slow-NBN articles miss. If you're on FTTN or FTTC, there's a good chance you can get a full fibre upgrade for free, and most people don't know it exists.

NBN Co has been rolling this out for a couple of years now. More than 5 million premises have already become eligible, and around 800,000 had upgraded by mid-2025. Plenty more are still sitting on copper not realising the offer is on the table.

Who's eligible right now

If you're on FTTN or FTTC and you live in an area where NBN Co has rolled fibre past your premises, you're likely eligible. The program covers most metropolitan areas and a lot of regional Australia.

To trigger the free upgrade, you currently need to order an NBN 500 plan or faster from a participating provider. From July 2026, that speed-tier requirement is being dropped for FTTC customers, and forced upgrades will begin for areas being phased off copper entirely.

How to check your address

Go to nbn.com.au, run your address through the address checker, and it'll tell you what technology you're currently on and whether you're eligible for an upgrade.

If it says "available" or "eligible", you're ready to go. If it says "not currently available", check back every few months as the rollout is still expanding.

What's involved and what it costs you

For the customer, the fibre install itself is free. Your provider organises an NBN technician visit, they run new fibre from the street to a small NBN connection box mounted on an internal wall, and the existing copper service is decommissioned.

The visit usually takes 2 to 4 hours. Some installs need a pre-visit to assess access, which can drag the process to a few weeks total from order to active service.

The catch is the plan. Most customers need to commit to an NBN 500 plan or faster to qualify, and that plan will probably cost more per month than what you were paying. But if you've been wearing years of unreliable FTTN, the maths usually works in your favour.

I'm currently working with a customer in this exact situation. They had no idea the free fibre upgrade existed and were copping years of unreliable FTTN speeds while paying full whack on a 100/20 plan their line couldn't deliver. The modem was also on its way out, which was making everything feel worse.

Helping them through the upgrade fixes both problems at once. New fibre line, modern modem-router that can actually handle the new speeds, and a plan that delivers what's promised. Not bad for a free install.

This is happening across Australia right now. If your speeds have been bad for years on FTTN or FTTC, this is the most worthwhile bit of admin you'll do all year.

Slow because of your provider

Even when the line is healthy, your provider can still be the problem. Each retail ISP buys wholesale capacity from NBN Co and divides it among their customers. How much they buy, and how they manage congestion, varies wildly between providers.

Peak-hour congestion (7 to 11 pm)

The classic pattern: speeds are fine all day, then crash from around 7 pm onwards. By 8 or 9 pm you can barely load a webpage. By midnight, everything's back to normal.

This is almost always provider congestion, not NBN line congestion. Peak hours hit when most of the country is home from work and streaming, gaming, or video calling. If your provider hasn't bought enough wholesale capacity to handle the load, your speeds get throttled by the bottleneck.

The pattern is especially common with cheaper unlimited-data providers. We see it constantly with budget-tier resellers who price aggressively and ration backhaul to make the margins work.

What CVC capacity actually means

CVC stands for Connectivity Virtual Circuit. It's the wholesale bandwidth a provider buys from NBN Co for each Point of Interconnect, which is the regional aggregation point your traffic flows through.

Buying enough CVC to handle peak load is expensive. Cheap providers tend to under-provision and rely on most customers not actually using their connection at full speed. When everyone tries to stream at once, that bet falls apart.

The ACCC has been progressively pushing providers to disclose typical evening speeds for exactly this reason. If your provider's quoted typical evening speed is well below the headline plan speed, that's CVC under-provisioning visible on your bill.

Provider patterns we see in the field

Without naming individual providers, the patterns are consistent. Premium providers (the ones charging $80 to $120 a month for a 100 Mbps plan) generally provision enough CVC to deliver close to plan speeds in evenings. Budget providers ($60 to $75 for the same nominal plan) often don't.

If you're paying budget pricing and seeing budget-level congestion, that's the trade-off you signed up for, even if the marketing didn't make it clear.

The fix is straightforward in theory: switch to a provider known for better evening speeds. In practice, switching is fiddly and you might be locked into a contract. The ACCC's regular speed monitoring publishes actual evening-speed data for the major providers if you want to compare before switching.

Slow because of your home setup

Plenty of "slow NBN" complaints turn out to have nothing to do with the NBN at all. The problem is something in your house.

The September 2025 speed boost (and why your modem might now be the problem)

In September 2025, NBN Co launched new high-speed tiers and most major providers automatically migrated existing customers up. The headline speeds doubled or quintupled overnight, with no change to the bill.

If you were on a 100/20 plan, you're probably now on 500/50. 250/25 plans went up to 750/50, and 500/50 plans went up to roughly 1Gbps.

The catch is that a lot of modems can't actually deliver the new speeds. WiFi 5 (802.11ac) modems have a real-world ceiling around 200 to 400 Mbps in most homes, even when the line will deliver 940. WiFi 6 is the practical minimum for properly using anything above 250 Mbps over Wi-Fi.

If your modem is more than three or four years old and your speeds suddenly feel disappointing, the line probably got faster while your gear stayed the same. We see this constantly across the network right now.

Wi-Fi vs Ethernet performance gap

Even on a brand-new modem, Wi-Fi will always be slower than Ethernet. That's physics, not a fault. Walls, distance, interference from other Wi-Fi networks, and the limits of your phone or laptop's Wi-Fi chip all eat into the speed.

A typical phone in the next room might get 200 Mbps over Wi-Fi from a connection that delivers 940 over Ethernet. That's not a problem with the NBN or your provider, that's just how Wi-Fi works.

If you've been auto-boosted to a faster plan and you want to actually use the new speed, plug your main devices into Ethernet where you can. The Smart TV, the gaming console, the home office desktop. Wired connections won't compete for airtime with the rest of the house.

Channel congestion in apartments and dense suburbs

In apartment blocks and tightly-packed suburbs, your Wi-Fi has to compete with every other Wi-Fi network in range. The 2.4 GHz band is especially crowded because it has limited channels and longer reach.

If you're in this situation, switching your devices to 5 GHz or upgrading to a mesh system with proper channel management can recover meaningful speed without changing anything about your NBN connection. The mesh question is worth its own conversation if you're seeing this pattern.

Too many devices, or one device hammering the line

NBN Co's own 2025 data shows the average Australian household is now running 22 connected devices. Smart TVs, phones, tablets, security cameras, smart bulbs, voice assistants, doorbells, gaming consoles. Each of those is on the network whether you're using it or not.

A single device backing up to the cloud, downloading a Windows update, or streaming 4K can hog enough bandwidth to make everything else feel slow. Modern routers can prioritise traffic and cap individual devices, but most ISP-supplied modems don't have those features turned on by default.

If your speeds are fine sometimes and unusable other times with no obvious pattern, this is often the explanation. Check what's running in the background before you blame anyone else.

When the home setup is the bottleneck, sorting it properly often delivers a bigger speed bump than upgrading the plan. Replacing an old modem, running Ethernet to the lounge, or putting in a proper mesh system can transform what feels like a slow NBN problem in a single visit.

Quick wins before you call anyone

If you've worked through the previous sections and you're not sure where the bottleneck is, here are the things to try before you call your provider or a tech.

Restart in the right order

Power off your modem first, then any separate router, then your devices. Wait 30 seconds. Power them back on in reverse: modem first, router next, devices last.

This clears stale connections, forces a fresh handshake with the NBN, and resolves a surprising number of "it was working yesterday" complaints. Worth doing once a month even when things seem fine.

Check Ethernet vs Wi-Fi

Plug a laptop directly into the modem and run a speed test. If that test hits your plan's typical evening speed, the NBN and your provider are both fine and the issue is somewhere in your Wi-Fi.

If the Ethernet test is also slow, the problem is upstream and Wi-Fi changes won't fix it.

Move the modem

Modems work best in central, elevated positions. If yours is tucked in a low cupboard near the front door, the Wi-Fi has to push through walls and furniture to reach the rest of the house.

Moving the modem to a more central, higher position can lift Wi-Fi speeds across the whole home without changing any settings. We see this fix slow-Wi-Fi problems regularly.

Update modem firmware

Most modems get firmware updates from the manufacturer that fix bugs and improve performance. Most modems also don't apply those updates automatically.

Log into the modem's admin page (usually at 192.168.0.1 or 192.168.1.1, the password is usually printed on the device itself) and check for a firmware update option. If one's available, run it. The modem will reboot, and that's normal.

Kill background bandwidth hogs

Cloud backup services like OneDrive, Dropbox, and iCloud can use as much bandwidth as you give them. So can Windows updates, Steam game updates, and macOS background syncs.

Check what's running on every device in the house. Pause anything that doesn't need to run right now and see if speeds improve. If they do, set bandwidth limits so it doesn't happen again.

When to call your provider vs when to call a tech

By this point you should have a sense of where the bottleneck lives. The next question is who's actually going to fix it.

Signs it's an NBN or ISP fault

Call your provider first if your speeds are bad on Ethernet across multiple times of day, the line drops out completely several times a day, the lights on your NBN connection box show red or are off, or your speeds suddenly halved with no other change.

These are line-level or provider-level issues that you can't fix from your side. The provider can run diagnostics, raise a fault with NBN Co, and dispatch a technician if needed.

When you call, have your speed test results ready (Ethernet, multiple times of day, with screenshots), your plan name, your NBN connection type, and the model of your modem. Skipping straight to a Level 2 technician saves a lot of script-reading.

Signs it's something in your house

Call us in if Ethernet speeds are good but Wi-Fi is slow, your speeds are fine sometimes and bad other times with no obvious pattern, you've been auto-boosted to a faster plan and want to actually use the new speed, your modem is more than three years old, or you're not getting good coverage to all rooms.

These are home-network problems, not NBN problems. A proper site visit usually finds a single bottleneck (old gear, bad placement, wrong settings) and fixes it.

We can also help with the FTTP upgrade process if you're eligible. Sorting the right plan, dealing with the install, replacing old gear with something that can handle the new speeds, all in one visit.

Need a hand getting it sorted?

If your NBN's been doing your head in and you're not sure where to start, we can help. Our technicians sort slow internet across Australia every day, work with every major NBN provider, replace old gear with the right modern kit, and run cabling where it makes sense.

Get in touch with Jim's IT and we'll send someone out to take a proper look.

Frequently Asked Questions

Why is my NBN slow at night specifically?

If your speeds are fine during the day and crash between 7 and 11 pm, you're almost certainly seeing peak-hour congestion at your provider. NBN Co rarely runs out of capacity at the line level. Your provider's wholesale CVC capacity, on the other hand, is shared across all their customers in your area.

Cheaper unlimited providers tend to under-provision their CVC to keep prices low. The fix is either upgrading to a provider known for better evening speeds, or accepting it as the trade-off for a cheap plan.

How do I check what NBN technology I'm on?

The easiest way is to enter your address into the NBN Co website and use their address checker. It'll tell you exactly what technology services your premises.

You can also tell from the equipment in your house. A small white NBN connection box mounted to an internal wall usually means FTTP or HFC. A modem with a phone-style cable running into the wall usually means FTTN or FTTC. A satellite dish or roof-mounted antenna means Sky Muster or Fixed Wireless.

Is the free FTTP upgrade really free?

The fibre install itself is free. NBN Co covers the cost of running new fibre from the street to your home and decommissioning the old copper.

The catch is that you generally need to commit to an NBN 500 plan or faster to qualify, which usually costs more per month than your old plan. From July 2026, that requirement is being dropped for some FTTC customers, and forced upgrades will begin for areas being phased off copper entirely.

Will a new modem actually fix my NBN speed?

If you've been auto-boosted to a faster plan since September 2025 and your modem is more than three years old, almost certainly yes. WiFi 5 modems can't deliver more than around 200 to 400 Mbps over Wi-Fi in most real-world setups, even when the line will give you 940.

If your line is delivering its plan speed on Ethernet but Wi-Fi feels slow, a new WiFi 6 modem will usually solve it. If Ethernet is also slow, a new modem won't help. The issue is upstream of your home.

Was I automatically moved to a faster plan in September 2025?

Probably yes if you're on FTTP or HFC. NBN Co launched new tiers in September 2025, and providers including Telstra, Optus, Aussie Broadband, Superloop, Tangerine, More, Vodafone, Dodo, and iPrimus automatically boosted existing customers' plans.

If you were on 100/20, you're now on 500/50. 250/25 plans went to 750/50. The wholesale price didn't change, so most providers passed the upgrade through at no extra cost. Check your latest bill or your provider's website if you're not sure.

Will changing providers fix slow NBN?

If your speeds are bad in evenings only, switching to a provider with better CVC provisioning will likely fix it. Look at the ACCC's quarterly broadband performance reports to see actual evening speeds by provider rather than relying on marketing.

If your speeds are bad all the time including on Ethernet, a provider switch won't help. The issue is either the line itself, your modem, or your home setup. Switching providers under those conditions just gives you the same problem with a new logo on the bill.

How do I know if there's a fault on my line?

Look at the lights on your NBN connection box. If any are red, off, or rapidly flashing when they shouldn't be, there's likely a fault. Each NBN technology has a slightly different normal pattern, but green steady lights are generally good.

Run a wired speed test multiple times across the day. If you're consistently below 50% of your plan's typical evening speed on Ethernet at all times, that's strong evidence of a line-level fault that your provider should escalate to NBN Co.

Is the NBN really worse than other countries' broadband?

In raw speed comparisons, yes. Australia ranks lower than countries like Singapore, South Korea, the United States, and most of Western Europe. Recent global broadband data puts Australia around 60th in the world for fixed-line speeds.

The gap is closing as the FTTN-to-FTTP rollout continues, and Australia's geography (long distances, low population density outside cities) makes a fully fibre rollout genuinely harder than smaller, denser nations. By 2030, the FTTN network is scheduled to be retired entirely, which should bring Australian fixed-line broadband closer to international benchmarks.