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NBN Speed Test: How to Test & Fix Slow Internet

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NBN Speed Test: How to Test & Fix Slow Internet

This guide shows you how to accurately measure your NBN speed and what to do when it’s slower than what you’re paying for. You’ll learn the correct testing method, how to interpret the results, and a step-by-step troubleshooting path to improve your connection.

What You’ll Need

  • A computer or laptop with an Ethernet (network) cable – Wi-Fi results can vary due to interference.
  • Your NBN modem/router and its power supply.
  • Your plan’s advertised speed (check your provider’s app, email, or bill).
  • A speed test website or app – popular options include Ookla Speedtest, Fast.com, and the ACCC’s official NBN speed test.
  • Access to your router’s admin page (usually via a web browser at an address like 192.168.0.1 or 10.0.0.1 – check the sticker on the router).

Step-by-Step

  1. Close all unnecessary programs and apps on the device you’re using. Background downloads, streaming, and cloud backups can eat bandwidth and skew the test.
  2. Connect your computer directly to the modem/router via Ethernet cable. Plug one end into your computer’s network port and the other into one of the router’s LAN ports (usually yellow or numbered). If you’re using a laptop without an Ethernet port, you may need a USB-to-Ethernet adapter.
  3. Restart your modem/router. Unplug the power cord, wait 30 seconds, then plug it back in. Wait until the internet light is solid (usually 1–2 minutes). This clears temporary glitches.
  4. Disable Wi-Fi on the test device (or turn off Wi-Fi on other devices) to ensure the test uses the wired connection only.
  5. Open a speed test website in your browser. If you’re on an NBN plan, the ACCC’s official test (nbnco.com.au/speedtest) is designed to reflect your plan’s maximum speed. Ookla Speedtest is also reliable.
  6. Run the speed test. It will measure three things: download speed (how fast data comes to you), upload speed (how fast data goes from you), and ping/latency (response time).
  7. Run the test at least three times at different times of day (e.g., morning, evening, weekend). Take note of the results.
  8. Compare your results to your plan’s speed tier. For example, NBN 50 plans should deliver around 50 Mbps download; NBN 100 around 100 Mbps. The ACCC test will show whether you’re getting the “typical evening speed” for your plan.
  9. If speeds are significantly lower than expected (e.g., below 50% of your plan’s max), proceed to troubleshooting below.

Common Mistakes

  • Testing over Wi-Fi. Wi-Fi is affected by distance, walls, and interference from neighbours. Always test via Ethernet for a true NBN speed.
  • Testing during peak hours. NBN speeds naturally slow during 7–11 PM when everyone is online. Compare your results to your plan’s “typical evening speed,” not the maximum.
  • Having other devices active. Streaming, gaming, or even smart home devices can consume bandwidth. Pause them during the test.
  • Using an old or slow device. An old computer or one with a slow hard drive can bottleneck the test. Try a different device if possible.
  • Not restarting the modem before testing. A long-running router may have degraded performance. A quick reboot can fix that.

Tips

  • Use the ACCC NBN speed test – it’s designed to match your plan’s speed tier and gives a clear “pass/fail” against what you’re paying for.
  • Test at different times to see if the issue is peak-hour congestion or a constant problem.
  • Keep your router’s firmware updated. Check the admin page for a firmware update option.
  • Position your router centrally if you use Wi-Fi, away from walls and metal objects.
  • Use a wired connection for important activities like video calls or gaming, even if your Wi-Fi seems fine.

Troubleshooting

If your speed test shows results well below your plan’s minimum (usually 50% of the max), work through these steps in order:

  1. Check the NBN connection box. For FTTP (fibre to the premises), the NBN connection box should have a solid green light. For FTTC/FTTB, check the little white NBN box. If any light is red or flashing, note the pattern – it may indicate a fault.
  2. Test with a different Ethernet cable. A damaged cable can cause massive speed drops. Try a known-good cable.
  3. Connect your computer directly to the NBN connection box (bypassing your router). For FTTP, plug the Ethernet cable into the UNI-D1 port. For other types, you may need to use the modem’s WAN port. If speeds improve, your router is the problem.
  4. If the router is the issue, try a factory reset. Press and hold the reset button (usually a small pinhole) for 10 seconds. You’ll need to reconfigure Wi-Fi and any custom settings.
  5. Check for internal wiring issues. If you have a phone line or wall sockets for FTTC/FTTB, try a different wall socket if available. Loose or old wiring can reduce speeds.
  6. Contact your internet provider. Have your speed test results ready. They can check your line sync rate and may send a technician if needed.
  7. If your provider says the line is fine but speeds are still low, complain to the TIO (Telecommunications Industry Ombudsman) – they handle unresolved speed complaints.

Frequently Asked Questions

What is a good NBN speed?

It depends on your plan. NBN 25 should give around 25 Mbps, NBN 50 around 50 Mbps, and NBN 100 around 100 Mbps. For most households, 50 Mbps is enough for streaming and browsing; 100 Mbps is better for multiple heavy users.

Why is my NBN slower at night?

This is normal. During peak hours (7–11 PM), more people are online, causing congestion on the NBN network. Your plan’s “typical evening speed” reflects this – for example, NBN 50 plans typically deliver around 40 Mbps in the evening.

Does the type of NBN connection matter? (FTTP, FTTC, HFC, etc.)

Yes. Fibre to the premises (FTTP) generally offers the most stable speeds, while Fibre to the Node (FTTN) can be slower due to copper wiring. HFC (cable) is usually reliable but can be affected by network congestion.

Can I improve my NBN speed without changing plans?

Often yes. Try repositioning your router, using a wired connection, updating firmware, or moving to a less congested Wi-Fi channel. If the problem is the NBN line itself, you may need a technician.

Why does my speed test show high download but low upload?

Upload speeds are typically much lower than download on NBN plans (e.g., 20 Mbps upload on a 100 Mbps plan). If upload is drastically lower than expected, check for background uploads or contact your provider.

What should I do if my speed is consistently below the minimum?

Contact your provider with your test results. If they can’t fix it, you can lodge a complaint with the TIO. Under ACCC rules, providers must offer a remedy if you’re not getting the speed you pay for.

Related

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.