What Is Bufferbloat?
Bufferbloat causes lag during downloads. Learn what it is, how to detect it, and how to fix it with a free speed test.
Bufferbloat happens when your router or modem queues too much traffic in large buffers. Downloads look fast, but latency spikes whenever the link is busy—gaming and calls suffer.
SpeedIP runs a bufferbloat grade during full speed tests by measuring ping while the connection is under load. An A or B grade means your router handles congestion well; D or F suggests you need QoS or a smarter queue discipline.
Run a full test below to see your bufferbloat grade alongside download and upload speeds.
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Frequently Asked Questions
How do I know if I have bufferbloat?▾
If ping jumps when someone starts a download or upload, you likely have bufferbloat. SpeedIP's grade summarizes this during a full test.
Can bufferbloat be fixed?▾
Yes—enable SQM or cake/fq_codel on supported routers, limit device upload speeds, or upgrade to a router with modern queue management.