Testing your BT Broadband connection
BT sells Full Fibre (fibre to the home on the Openreach network) and older Fibre plans over copper from the street cabinet. With Full Fibre, an Openreach ONT box brings the fibre into your home and the BT Hub connects to it. BT publishes a Stay Fast Guarantee for each package, measured to the Hub.
This test detects your provider automatically and measures download, upload, ping, jitter and latency under load against the nearest server on Cloudflare's network. Enter your plan speed under the result to see the percentage you really get.
BT Broadband speeds by plan
| Plan | Download | Upload |
|---|---|---|
| Full Fibre 150 | about 150 Mbps | about 30 Mbps |
| Full Fibre 300 | about 300 Mbps | about 49 Mbps |
| Full Fibre 500 | about 500 Mbps | about 73 Mbps |
| Full Fibre 900 | about 900 Mbps | about 110 Mbps |
| Fibre 1 / Fibre 2 (part fibre) | about 50 to 74 Mbps | about 9 to 20 Mbps |
Average speeds as published for each package. Openreach full fibre is asymmetric: upload is lower than download on every BT tier. Checked on 31 October 2026; tiers change and vary by address, so confirm on the BT Broadband website.
What result should you expect?
On Full Fibre 900 a wired test usually shows 850 to 940 Mbps down and about 110 Mbps up. Over the Hub's Wi-Fi, 300 to 600 Mbps is common. On part fibre, speed depends on the copper distance to the cabinet.
Measure your connection now. Start the test
Common reasons for slow BT Broadband speeds
- Hub Wi-Fi limits: test plugged into the Hub with Ethernet before blaming the line.
- Red light on the Openreach ONT: the fibre signal is lost; see red LOS light.
- Below the Stay Fast Guarantee: keep dated wired tests; under Ofcom's speed code you can ask BT to fix it.
- Part fibre slow: read speed up slow DSL and check whether Full Fibre is available.
Before contacting BT support
- Restart the Hub; with Full Fibre, check that the ONT lights are steady.
- Run the BT Hub's own speed check and our test over Ethernet.
- Check the BT app for service status in your area.
- If speeds stay below your plan, check for traffic throttling, then contact support with your saved results.
More help: slow internet: causes and fixes and all providers we cover.
Sources
SpeedFibre is an independent website, not affiliated with BT Broadband. The provider's name is used only to describe the service being tested.
Frequently asked questions
What is BT's Stay Fast Guarantee?
It is a minimum download speed BT commits to for each package, measured to the Hub. If you regularly get less and BT cannot fix it, you can claim under the guarantee.
Why is my BT Full Fibre upload only about 110 Mbps?
Openreach full fibre packages are asymmetric. On Full Fibre 900, an upload of about 110 Mbps is the published average.
Is there a separate box for BT Full Fibre?
Yes. The Openreach ONT terminates the fibre and the BT Hub plugs into it with an Ethernet cable.
