If you've been worried that running Ookla's network testing app or any other similar app would run you afoul of your monthly data cap, worry no longer. At least, if you're a T-Mobile subscriber. The carrier has come out to confirm that data transmitted via network speed tests won't count towards a user's regular data usage.
Imagine if you only had 1 GB of high-speed data to use up per month and a speed test, for some reason, transmits something as large as 256 MB. Normally, you'd have already consumed a fourth of alloted usage just to test how fast the network theoretically is (whether you actually buy into such speed test suites is another matter entirely). For T-Mobile, however, that shouldn't be a reason for any subscriber to fret. as those won't count anymore.
"The Ookla Speedtest.net application is designed to measure true network speed--not show that a customer has exceeded their high-speed data bucket. Other speed test providers are also whitelisted."
This could easily be likened to the carrier's new Music Freedom announced just last week. In a nutshell, T-Mobile is offering unlimited music streaming that won't count towards subscriber's monthly limits. Speedtest data will likely be treated the same. The carrier has countered net neutrality criticisms about these exclusive features, claiming that data from these types of content aren't treated differently in a priority lane and neither are there any financial deals involved. It is simply just not counting the data at all.
In the final analysis, the speedtest exception is basically a marketing tactic. T-Mobile just wants everyone to know how fast its network really is, even if you have reached your monthly limit, and what you're missing out on if that's the case.