Slow internet at home is one of the most common tech frustrations in New Zealand, and the plan you pay for is rarely the real culprit. Far more often the bottleneck sits somewhere between the fibre box and your device: the Wi-Fi inside the house, the type of connection reaching the property, or a single gadget quietly swallowing the bandwidth. The good news is that most causes are easy to identify once you know what to look for. The way internet access is delivered to a home varies a lot — fibre, fixed wireless, copper and satellite each have their own ceiling — so the fix depends on which link in the chain is failing. This guide works through the causes in a sensible order, from the checks that take a minute to the ones that need a call to your provider, so you can find the one holding you back instead of guessing.
Key points
- Test wired first, then Wi-Fi. The gap between the two results shows whether the problem is inside your home or on the line.
- Most slowdowns are Wi-Fi, not the plan. Distance, walls, the 2.4 GHz band and old modems are the usual culprits.
- Copper is much slower than fibre and is being switched off by 2028 — if fibre is available, that is the real fix.
- Evening-only slowdowns mean congestion — a shared fixed-wireless cell or your provider’s capacity.
- Check for faults last: a red LOS light, constant reconnecting or a whole street affected points to a network outage.
Start by working out what kind of slow you have
Before changing anything, find out where the slowdown lives. Run a speed test twice: once on a laptop plugged into the modem with an Ethernet cable, and once over Wi-Fi from the room where the problem is worst. The gap between those two numbers tells you almost everything. If you are not sure how to read the result, our guide to running an internet speed test in NZ walks through it step by step.
Interpret the two results like this:
- Wired fast, Wi-Fi slow: the problem is inside the house — look at causes 1 to 4.
- Both slow, all day: the plan, the modem or the connection type — causes 5 to 8.
- Fine by day, slow in the evening: congestion — causes 9 and 10.
- Slow and dropping out: most likely a fault — causes 11 and 12, plus our guide to connections that keep dropping out.
Do this before you spend a cent on new hardware or a bigger plan. Upgrading the plan when the real problem is a distant modem or an old cable just buys speed you still cannot reach.
The twelve causes, in the order worth checking
1. Wi-Fi distance and the walls in between
Wi-Fi signal falls off sharply as it passes through concrete, brick, tile, and the foil backing in some insulation. A modem tucked into a garage, a hallway cupboard or a corner of the house simply cannot cover the far bedroom. The single most effective free fix is to move the modem to a central, elevated spot — on a shelf rather than the floor, and out in the open rather than behind a TV. Where the layout makes central placement impossible, a mesh system spreads coverage far better than a single box; our Wi-Fi extender and mesh guide explains which option suits which type of house.
2. Stuck on the crowded 2.4 GHz band
Most modems broadcast on two or three bands. The 2.4 GHz band reaches furthest but is slow and shared with almost everything else in the neighbourhood — other networks, microwaves, baby monitors and cordless phones. The 5 GHz band is much faster over shorter distances, so connect the devices you care about to it. Newer modems also use the lower 6 GHz band, opened for Wi-Fi in New Zealand in 2023 and available on Wi-Fi 6E and Wi-Fi 7 equipment such as Spark’s 5G Gateway 7 and One NZ’s Deco BE28; if your gear supports it, reserve it for the devices closest to the modem. The rules for that band are set by Radio Spectrum Management.
3. An old or underpowered modem
A modem supplied with a plan you signed years ago may top out well below your current fibre speed, especially over Wi-Fi. Older Wi-Fi 5 hardware struggles to push much beyond 200 to 300 Mbps in a real home, even when the line can deliver far more. If a wired test hits your plan speed but Wi-Fi lags badly on a modern phone or laptop, the router is the limit. Most providers will replace ageing hardware cheaply or free when you re-contract, so it is worth asking; our guide to modems and routers in NZ covers what to look for.
4. Too many devices, or one saturating the link
A games console downloading an update, a cloud backup running in the background, or a laptop syncing photos can quietly take everything the connection has. Open your modem’s admin page or app and look at the list of connected devices, then pause whatever is mid-transfer. Security cameras that upload footage constantly are a common hidden load, as are automatic system updates that kick off at the worst moment. If speed only sags at certain times, this is often why.
5. The plan itself is wrong for the household
Check what you are actually paying for, then compare it to your wired test. Since June 2025, Chorus’s Big Fibre Boost lifted the old 50/10 wholesale plan to 100/20 and the popular 300/100 plan to 500/100 at no extra wholesale cost for around 700,000 homes, as RNZ reported. If your wired test still shows the old figure, the boost may not have been passed on — call and ask. If it has been applied and speed is still short for the number of people streaming and working at once, the plan may genuinely be too small; our guide to what internet speed you actually need helps you decide.
6. Copper instead of fibre
If your home still runs on copper, that alone can explain the slowdown. The Commerce Commission’s independent testing puts VDSL at around 63 Mbps down and 21 Mbps up, and older ADSL at roughly 11 Mbps down and just 1 Mbps up — against about 106 Mbps for the entry fibre plan and around 877 Mbps for Fibre Max. Copper is also on the way out: Chorus has brought the nationwide switch-off forward to 2028, and only around 53,000 copper connections remained by the March 2026 quarter, down from 63,000 three months earlier. You can follow the details in the Commerce Commission’s Measuring Broadband New Zealand reports and the Telecommunications Forum’s copper retirement pages. Where fibre is available, moving to it is the fix — not a faster copper plan, which does not exist.
7. Fixed wireless slowing in the evening
Fixed wireless sends your broadband over the mobile network, so it shares capacity with every phone on the same cell. In the Commission’s measurements, 4G fixed wireless averaged about 66 Mbps across the day but fell to roughly 52 Mbps at peak, with latency near 48 ms — noticeably higher than fibre. That is why it can feel fine at lunchtime and crawl once the neighbourhood comes home. If fibre is not an option, 5G fixed wireless is considerably faster, and Starlink satellite commonly measures between about 130 and 250 Mbps depending on plan and time of day.
8. A 100 Mbps bottleneck hidden in the chain
Sometimes the line is fast but something in the path is not. Older network switches, powerline adapters, some smart-TV Ethernet ports and cheap or damaged cables cap out at 100 Mbps — Fast Ethernet rather than gigabit. A tell-tale sign is a wired test on a Fibre 500 plan that stubbornly reads about 94 Mbps: that is a Fast Ethernet ceiling, not a slow connection. Swap the cable for a Cat 5e or Cat 6 one, plug straight into the modem to test, and replace any old switch between the modem and the device.
9. Congestion at your provider
Fibre itself barely changes at peak. Fibre 500 measured about 508 Mbps by day and 506 Mbps in the evening, so the technology is not the problem. If your wired evening result is far below the daytime one, the constraint is more likely your provider’s own capacity. Log a week’s worth of morning and evening wired tests, then raise it with your provider using that record; our guide to NZ internet providers covers the complaint path and how to switch if nothing improves.
10. Malware, adware and browser clutter on one device
If a single device is slow while everything else on the network is fine, the device is usually the problem, not the internet. Malware, hidden crypto-mining scripts, a pile of browser extensions and a browser holding hundreds of open tabs all show up to the user as “slow internet”. Run a full security scan, remove extensions you do not recognise, and restart the browser. Our plain-English malware explainer covers the signs worth watching for.
11. Slow DNS lookups
DNS is the system that turns a web address into the numeric location your device actually connects to. If pages take a long time to start loading but then download quickly once they do, slow name lookups are the likely cause. Pointing your router at a faster public resolver often helps — our guide to changing DNS on a router shows how — and flushing the DNS cache clears stale entries on a single device.
12. A genuine fault or outage
Some slowdowns are simply a broken connection. A fibre box showing a red LOS (Loss of Signal) light, a modem that keeps reconnecting, or a whole street affected at once all point to a network fault rather than anything in your home. Check the provider status pages and the Chorus outages map — see our NZ outage guide and the official Chorus internet outages map — and read our guide to what each light on the fibre box means before you call for a technician.
Connection types and the speeds to expect
Much of the diagnosis above comes down to knowing what “normal” looks like for your connection. The table below pulls together the typical measured download speeds and latency for each mainstream New Zealand technology, drawn from the Commerce Commission’s testing. Treat them as national averages: any single line will differ, but they are a useful yardstick for judging whether your result is reasonable or a sign that something is wrong.
Connection speeds compared
| Connection type | Typical measured download | Latency | Notes |
|---|---|---|---|
| Fibre Max | ~877 Mbps (line max ~940) | ~7 ms | Fastest mainstream option; barely changes at peak |
| Fibre 500 | ~508 Mbps (day) / ~506 (peak) | ~7 ms | Most popular tier since the 2025 boost |
| Fibre 100 | ~106 Mbps | ~8 ms | Entry fibre, now delivered as 100/20 |
| VDSL (copper) | ~63 Mbps down / ~21 up | Higher than fibre | Being retired by 2028 |
| ADSL (copper) | ~11 Mbps down / ~1 up | High | Oldest technology; being retired |
| 4G fixed wireless | ~66 Mbps (day) / ~52 (peak) | ~48 ms | Shared mobile cell; slows in the evening |
| 5G fixed wireless | Much faster than 4G; varies by coverage | Lower than 4G | Good where fibre is unavailable |
| Starlink (satellite) | ~130–250 Mbps | ~40 ms | Rural option; tends to slow 7–11pm |
When a VPN is the thing slowing you down
A VPN (virtual private network) encrypts your traffic and routes it through one of its servers, which adds a little overhead and some extra distance. Connected to a server in Auckland, the cost is small and usually unnoticeable. Connected to Los Angeles it adds around 140 ms of latency, and throughput drops with it; London is further again. If the internet feels slow only while the VPN is switched on, the fix is to choose a closer server or a faster protocol such as WireGuard, which is lighter than older options. Once you know where the real bottleneck is, our guide to testing and optimising your connection speed walks through the remaining settings worth changing.
Disclaimer: this article is general information only. The measured speeds quoted are national averages from the Commerce Commission’s Measuring Broadband New Zealand programme (Report 28, July 2026) and will differ from any single connection. Always check current plan details with your own provider.
Reference sources
Frequently asked questions
Why is my internet slow all of a sudden?
Usually a device on the network has started a large download, update or backup, or the modem simply needs a restart. Run a wired speed test, check the modem’s list of connected devices, and power-cycle both the modem and the fibre box before assuming anything is broken.
Why is my internet slow only at night?
Almost always congestion. On fixed wireless it is the shared mobile cell filling up; on fibre it is more often Wi-Fi interference from neighbours or your provider’s evening capacity. A wired test taken in the evening tells you which, because it removes Wi-Fi from the equation.
Why is my Wi-Fi slow but Ethernet fast?
That points squarely at the Wi-Fi itself: distance, walls, the crowded 2.4 GHz band, or an ageing modem. Move the modem somewhere central, connect to the 5 GHz or 6 GHz band, or add a mesh unit. Paying for a faster plan will not change it.
Will a faster plan fix slow internet?
Only if a wired test already matches your current plan speed and the household genuinely needs more. If the wired test comes in far below what you pay for, a bigger plan just buys headroom you cannot reach — fix the actual bottleneck first.
Does a VPN slow down internet in New Zealand?
A little on a local server, and a lot on a distant one. Connecting to Sydney adds roughly 30 ms of latency, Los Angeles about 140 ms and London around 265 ms, all before the VPN’s own encryption overhead. Choosing a nearby server keeps the slowdown minimal.
Is copper broadband slower than fibre?
Considerably — around 63 Mbps for VDSL and just 11 Mbps for ADSL, against about 106 Mbps for entry-level fibre and 877 Mbps for Fibre Max. Copper is also being switched off nationwide by 2028, so where fibre is available, moving to it is the long-term fix.
