Bufferbloat Test
Measures how much your latency increases under full load. Grades A–F. Runs entirely on this site — no external tools.
Ready to test
Baseline
--ms
Under Load
--ms
Increase
--ms
Bufferbloat grades
A
No bufferbloat — your connection handles load perfectlyB
Minor latency under load — barely noticeableC
Moderate bufferbloat — video calls and gaming affectedD
High bufferbloat — latency spikes under normal household useF
Severe bufferbloat — connection degrades badly when loadedThis test saturates both download and upload simultaneously — the most realistic scenario for video calls and gaming.
What is bufferbloat?
Bufferbloat happens when your router or modem has an oversized data buffer. When the buffer fills up (during heavy use), packets have to wait in the queue — increasing latency dramatically. A plan that shows 500 Mbps on a speed test can have 200+ ms latency under load due to bufferbloat.
Symptoms: video calls dropping quality when others download, gaming lag spikes, web pages loading slowly at peak times.