Bufferbloat Test
Use the free test below to measure your connection right now. It adapts to your speed and finishes in under a minute.
How this speed test works
This test starts with a short latency probe, then downloads test data from Cloudflare's edge in increasing amounts until it can estimate your connection confidently. Slow links stop early; gigabit links scale up to get a stable reading.
The measurement engine begins with tiny requests and grows the transfer size stepwise, so the total data moved is close to the minimum needed for a confident number.
Adaptive testing also means the test is gentle on mobile data plans: it stops transferring as soon as the estimate is statistically stable.
Understanding download vs upload
Download is how fast data travels to you — it drives streaming, browsing and game downloads. Upload is the reverse and matters for backups, video calls and cloud work.
Latency is the round-trip time to our test server — small numbers are better for gaming and calls. Jitter measures the variation, and high jitter is what makes calls sound robotic even at low ping.
Factors that influence results
Your measured speed can vary with the time of day, the device's Wi-Fi generation, and how many other people are using the connection.
No single test can represent every destination on the internet, but a path to a major edge network is the standard, neutral way to benchmark a connection.
Getting the most from the test
Run the test a few times over a few days before drawing conclusions. One-off speeds are noisy; a median of several runs is a much more reliable picture of your connection.
Your data stays in your browser for the duration of the test; only a small, anonymous summary is saved afterward, and never the raw payload.
This test is free, requires no account, and never shows ads while it runs — the only goal of the measurement is to give you a trustworthy number as quickly as possible.
A few final tips
Bufferbloat Test is built to run on your connection in under a minute — press start, read the four numbers, and compare them with what your plan promises.
Speed test limitations
Wi-Fi adds its own variability. If your wired connection is much faster than your Wi-Fi, the bottleneck is your wireless link, not your ISP — and that is worth knowing before you call your provider.
Upload speeds can be throttled or capped separately from downloads on some plans, so a fast download with a slow upload is often the plan working as designed rather than a fault.
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