Bufferbloat test
Fast download speed doesn't stop lag. Bufferbloat is the ping spike that happens when someone in the house downloads something — and it ruins calls and games. This test loads your line and measures exactly that.
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| When | Down | Up | Ping | Loaded | Bloat | Server |
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Questions about this test
What is bufferbloat?
When your connection is saturated, routers and modems queue packets instead of dropping them, so everything waits in line. Ping that's 15 ms when idle can hit 300 ms+ under load. That's bufferbloat.
How is the grade calculated?
We measure idle ping, then keep pinging during the download and upload phases. The increase is graded: A+ under 5 ms, A under 30, B under 60, C under 200, D under 400, F above that.
How do I fix bufferbloat?
Turn on SQM, Smart Queue Management, fq_codel or CAKE on your router (OpenWrt, many ASUS, Ubiquiti, Firewalla, eero and others have it). Set the limits to ~90% of your real speeds. Grades typically jump from D/F to A.
Does a faster plan fix it?
Not by itself. Bufferbloat is a queue-management problem, so a 1 Gbps plan can grade F while a well-managed 100 Mbps line grades A.
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