Xfinity xFi Speed Test test your download speed. There is the option show more which starts the upload speed test and the latency test.

There is an option to choose another test server, however only American based servers might be selected.

### Free to use

Xfinity xFi Speed Test is free, there are no ads so the speed test earns 1 point.

### Easy to use

Xfinity xFi Speed Test passes the WCAG 2.0 Level AAA test, it earns 1 point.

To start the speed test 1 click is enough. So the Xfinity xFi Speed Test earns 1 points for this.

### Accuracy and consistency

Tested with a clean version of Chromium, throtteld at 30Mbps (30720 kbps) the following measurements are done.

Test Server: Seatle, WA

- 31.4Mbps (19 seconds)
- 31.5Mbps (19 seconds)
- 31.5Mbps (19 seconds)
- 31.5Mbps (19 seconds)
- 31.5Mbps (19 seconds)

Tested with a clean version of Firefox, throtteld at 30Mbps (Wi-Fi) the following measurements are done.

Test Server: Philadelphia, PA

- 31.6Mbps (26 seconds)
- 32.0Mbps (26 seconds)
- 31.6Mbps (25 seconds)
- 31.5Mbps (26 seconds)
- 31.9Mbps (26 seconds)

That gives an average of 31.6Mbps and a standard deviation of 0.19Mbps for the downloadspeed. The average and standard deviation for the time required are respectively 22 seconds and 4 seconds.

Note that based on the Chromium measurements the average download speed is 31.5Mbps with a standard deviation of 0.04Mbps. While the Firefox measurements gives an average download speed of 31.7Mbps with a standard deviation of 0.22Mbps.

Based on the measurements noted above you might conclude that the throttling speed of Firefox compared to the throttling speed of Chromium is not significant different.

## A test in the wild

Tested with Firefox the following measurements are done.

Test Server: Foxboro, MA

- 51.0Mbps (21 seconds)
- 50.8Mbps (20 seconds)
- 51.0Mbps (20 seconds)
- 50.9Mbps (20 seconds)
- 50.9Mbps (20 seconds)

That gives an average of 50.9Mbps and a standard deviation of 0.08Mbps for the downloadspeed.