Waveform's Bufferbloat test measures how much latency rises when your connection is saturated by uploads or downloads.

The test runs a baseline latency check, then repeats latency while performing a download and an upload speed test to compare the differences.

The page explains bufferbloat, gives pre-test advice (disable heavy tasks; use a wired connection when possible), and shows how results are graded and interpreted.

It lists routers and router features (SQM, DumaOS, IQrouter, Ubiquiti) that help mitigate bufferbloat, with shopping links and brief notes.