What Is Bufferbloat?
Last reviewed 2026-11-01
Bufferbloat is extra delay that appears when a full link queues packets. Learn how to see it and what a retest should show.
The symptom
A speed test can report plenty of megabits while a call or game falls apart the moment a download starts. The link is not “slow” in throughput. It is waiting in a queue.
Routers and modems buffer data so short bursts do not get dropped. When the buffer is large and unmanaged, every new packet waits behind a transfer that already filled the pipe.
How to see it
Measure idle HTTP latency, then measure it again while a download and an upload are running. The useful number is the increase, not a letter grade by itself.
MySpeedGauge’s grade is an internal scale documented on the methodology page. It is not a certification.
What to change, one step at a time
Pause other transfers and repeat the test. If the increase shrinks, something in the house was filling the queue.
If the router offers SQM or a simple QoS mode aimed at latency, enable it and repeat the same test. A smaller gap between idle and loaded latency is the result that matters.
Compare Ethernet with Wi-Fi only after the wired result is known. Do not replace hardware because a single wireless test looked uneven.