Bandwidth Calculator
Measure what your connection actually moves, in both directions. The test runs in your browser and adapts to your line, so a slow connection is never made to transfer more than it needs to.
Download
0.00Mbps
Upload
0.00Mbps
This measures your own connection to the nearest Cloudflare edge that fronts our site — not the link between two datacenters. Results vary with Wi-Fi, VPNs and other traffic on your line.
How the measurement works
The test transfers incompressible random data and times it. It starts with a small transfer and grows each pass based on the speed already observed, stopping at a time budget rather than a fixed size — that keeps a slow connection from having to move megabytes it will never finish quickly.
The figure reported is the best pass, not the average. Early small transfers are dominated by round-trip time rather than bandwidth, so averaging them in would under-report a fast line.
Frequently asked questions
- Why is the result lower than the speed my ISP sells me?
- Advertised speeds are a ceiling for the line into your home, measured under ideal conditions. What you get in a browser is affected by Wi-Fi, the devices sharing your connection, VPNs, and the distance to the server. A result within about 20% of the advertised figure over Wi-Fi is normal.
- Does upload speed matter for a VPS?
- It matters whenever you push data up: deploying code, restoring a backup, or uploading media. It does not affect how fast your site serves visitors, because that traffic leaves the server, not your home connection. If your upload is slow, move data server-side instead.
- How much data does the test use?
- At most about 25 MB per direction, and far less on a slow connection because the size adapts to what your line can actually move within the time budget.