Why internet speed tests disagree in Canada
A 400 Mbps result on one test and 66 Mbps on another does not automatically mean your connection changed. A test measures a path, a server and a method at a particular moment.
Start with the server
Your browser is only one end of a speed test. The other end is a measurement server or content network. A slow server, a distant route, congestion between networks, or a limit on the testing endpoint can lower the reported number even when your access line is capable of more. Testing services may select different nearby servers and therefore travel across different networks. M-Lab explains that server location, method and changing network conditions all contribute to differing results.
AI Speed measures traffic to this site's hosted endpoint. It does not measure the physical maximum of your fibre, cable or wireless connection. If another test gives a much higher result repeatedly, treat the lower result as a possible path or server limitation. It should prompt investigation, not a claim that your provider has reduced your plan speed.
Small requests can understate fast connections
A single small download spends a meaningful share of its time starting the request and waiting for a response. With a 400 Mbps connection, a one-megabyte file can arrive quickly enough that browser scheduling, server work and round-trip delay distort the estimate. A larger sustained transfer reduces that fixed overhead. Parallel transfers can make better use of a high-capacity path, although they also increase data usage and may produce a higher number than a single application flow.
AI Speed now warms the connection, reads streamed data from four parallel downloads, and measures the combined bytes over actual elapsed time. Upload uses parallel transfers too. The test stops at a time or data cap and reports what reached this endpoint. It does not include artificial waiting time in the Mbps calculation.
Compare results under the same conditions
Run each service several times, on the same device, within a short period. Pause large downloads, video calls and cloud backups. Test once over Ethernet if you can, then test Wi-Fi in the location where you normally work. A wired result close to your plan with a slower Wi-Fi result points toward local radio conditions or equipment. Distance, walls, interference and the Wi-Fi standard can all matter.
Record download, upload and latency separately. A fast download number does not guarantee low delay for video calls or games. If you compare providers, use repeatable test conditions and a representative sample at different hours. One result from one household is not a provincial or ISP average.
What does 50/10 mean?
The CRTC's universal service objective sets a target of at least 50 Mbps download and 10 Mbps upload access for Canadian homes and businesses. It is a policy target, not a promise that every test to every server will report precisely those values. Your retail plan, the technology serving your address and current conditions still matter.