A speed test that tells you what your connection can actually do
Real throughput, real latency under load, measured against M-Lab's open infrastructure — plus a plain answer on 4K streaming, calls, gaming, and downloads.
Why this beats a generic speed test
Bufferbloat, graded
Most tests hide what happens to your ping while the line is under load. We grade it A+ through F, because that’s the real reason calls and games stutter on a "fast" connection.
Answers, not just numbers
Every result is translated into a plain pass/marginal/fail for 4K streaming, video calls, gaming, downloads, and uploads — no guessing what your Mbps means.
A real waveform, not a fake dial
The live trace shows your connection’s actual behavior second by second — stutters and dips are visible, not smoothed away by a spinning gauge.
Frequently asked questions
What internet speed do I need for 4K streaming?
About 25 Mbps per 4K stream, and roughly 35 Mbps for 4K HDR. If several people stream at once, add the speeds together — three simultaneous 4K streams want around 75 Mbps of real, sustained throughput.
What is bufferbloat and why does it matter?
Bufferbloat is the latency spike that happens when your connection is busy: your ping climbs from, say, 15 ms to hundreds of milliseconds while someone uploads or downloads. It is why video calls freeze and games rubber-band even on fast lines. This test grades it A+ through F by measuring latency while your line is under load.
Why do my video calls stutter even though my download speed is high?
Calls depend on upload speed, latency, and jitter far more than download speed. A 500 Mbps download cannot compensate for an unstable upload or spiking ping during a call.
Is this speed test free, and is my data stored?
Yes, it is completely free and no account is needed. All measurement happens in your browser against public M-Lab (or Cloudflare) servers; no results are stored on this website.