What is Network Speed Test?

Test your internet connection speed directly on your device. Measures download speed by fetching test data and calculating throughput. Also estimates latency (ping) using resource timing. Results are displayed in Mbps with a visual gauge — no app installation or server signup needed.

Under the hood the test streams a real payload to and from Cloudflare's free speed endpoint over HTTPS. Download numbers come from how fast your device pulled a multi-megabyte chunk from the nearest Cloudflare edge. Upload numbers come from how fast random bytes posted back. Latency is the median of several small round trips. Nothing about the run is logged to our servers, and the payload bytes themselves are discarded at the edge once the timing is captured.

How to use

1. Click 'Start Test' to begin. The tool fetches a few megabytes from Cloudflare's free speed endpoint to time download, posts random bytes back to time upload, then pings the same endpoint to time latency.
2. Wait for the test to complete. Download speed, estimated upload speed, and latency are measured sequentially.
3. View your results on the speed gauge and compare with previous tests saved in your session history.

When to use

• Checking whether a slow video stream is your connection or the service.
• Comparing speeds before and after switching Wi-Fi bands or moving rooms.
• Logging quick readings during a remote support call to share with an ISP.

Result

Run a speed test and see results like: Download 85.4 Mbps, Upload (estimated) 22.1 Mbps, Latency 15ms. The gauge needle sweeps to your speed, and the result is added to the history chart below.

FAQ

How accurate are these results compared to Speedtest or Fast.com?

Expect readings within roughly 10-20% of Speedtest or Fast.com on the same connection. We start with a small probe to size the payload to your link, then sustain transfer for five seconds in steady state, sampling throughput every 250 ms and reporting the median. The upload runs over four parallel streams the same way desktop Speedtest does. Tools that pick a closer or farther server can land a few percentage points either side of ours.

Why is my upload speed shown as an estimate?

Most runs report a real measured upload now. The 'estimated' tag only appears when the upload POSTs to Cloudflare all fail (typically a corporate firewall, ad-blocker rule, or VPN that drops outbound to speed.cloudflare.com). In that case we fall back to an inference from your download speed and the typical asymmetry of your connection class, so the figure is approximate.

The latency number looks low. Does it include the route to a real server?

Latency is the median of several small HTTPS requests to Cloudflare's speed endpoint. It is real round-trip time to a nearby Cloudflare edge, not a device-API estimate. Latency to a specific game server, video-call host, or trading venue will differ because routing and the destination both matter.

Why does my speed change every time I run the test?

Wi-Fi interference, background downloads, VPN routing, and other devices on the same network all move the number. Your device also pools HTTP/2 connections, so the second test inside a minute usually reuses the same socket to Cloudflare's edge — and that socket inherits the prior run's congestion state, which reads ~20-40% lower even on a healthy link. We pause five seconds between consecutive runs and force the prior connection to drop, but the cleanest reading still comes from waiting a full minute between tests. Run three tests a minute apart and use the median rather than a single reading.

Does running this test use up my data plan?

Data usage scales with your connection speed because the test sizes its payload to fill about five seconds of steady-state transfer in each direction. A 25 Mbps DSL line will move around 30 MB total; a 200 Mbps cable line lands near 150 MB; a 1 Gbps fibre line tops out around 380 MB (capped so it never goes higher). That is in line with Speedtest and Fast.com, which routinely pull 50-500 MB depending on the link. Skip the test when you are on a tight metered plan.

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