Connection quality
Rough estimate of your current download speed.
Click Test connection to run a ~5 MB download test against Cloudflare's public speed endpoint.
Browser's own connection estimate
Some browsers expose an estimate via navigator.connection.
It's often cached and less accurate than running an actual test, but
useful as a sanity check.
Rough estimate only. A single-CDN browser test can't match dedicated services like Ookla or fast.com. Use the number as "is my connection working and roughly how fast" — not as a precise benchmark.
About this tool
This is a quick, rough estimate of your current download speed — enough to answer "is my connection broadly working and in the right ballpark?" without installing anything. It downloads roughly 5 MB from Cloudflare's public speed endpoint (speed.cloudflare.com/__down) and reports the throughput it observed. It is deliberately not a lab-grade benchmark: dedicated services like Ookla Speedtest and fast.com use clusters of servers and parallel streams that a single browser request can't match.
That's also why the number here usually reads a little lower than those services. A single-stream HTTP download from one endpoint is bounded by that one connection's behaviour — TCP slow-start, the distance to the nearest Cloudflare edge, and any momentary congestion — whereas multi-server tests saturate your line with many streams at once and report the peak. Treat this as a sanity check, not the figure to quote at your ISP. The browser's own Network Information API estimate is shown alongside as a second opinion, though it's a coarse, cached guess rather than a live measurement.
Read the result by band rather than by the exact megabits: a result in the tens of Mbps comfortably handles HD streaming and video calls; single-digit Mbps will struggle with 4K or several simultaneous streams; sub-1 Mbps points to a real problem worth chasing. Run it a couple of times — one low reading taken mid-download from something else on the network isn't conclusive. Nothing about the test leaves your browser beyond the download request itself.
How to use this tool
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Click Start
A ~5 MB test file begins downloading from Cloudflare's public speed endpoint. A single TCP connection, single stream — the kind of throughput a real download of a real file would actually see.
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Wait for the result
Typically 3-8 seconds, depending on your connection. Slower links take longer — a 5 Mbps line will spend about eight seconds downloading the test file.
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Compare with the Network Information API estimate
The browser's own guess at your downlink sits next to the measured value. If they disagree wildly, your connection is likely fluctuating — the browser's estimate is based on the last few seconds of background traffic.
Frequently asked questions
Why is the number lower than Ookla / fast.com?
Dedicated speed-test services spin up multiple test servers, run parallel streams, and pick the geographically closest node — all of which inflate the achievable number. We test a single stream from a single Cloudflare edge, which is still a real measurement but will typically read lower. The gap isn't measurement error; it's different methodology.
Why not an upload test too?
Upload testing needs a server endpoint that accepts POSTed bytes — our static site doesn't have one, and adding it would consume meaningful VPS bandwidth. Cloudflare's public upload endpoint is paid-only. For now, the tool is download-only by design.
What do the quality bands mean?
Excellent (≥100 Mbps) is gigabit / full-fibre territory. Good (25–100) handles 4K streaming and typical home broadband. OK (10–25) is enough for HD video. Slow (1–10) means video calls may buffer. Very slow (<1) means the connection is struggling.
Why is this slower than fast.com or Speedtest?
Commercial speed tests use multi-server, multi-stream infrastructure that saturates your line. This tool pulls a single ~5 MB file from one Cloudflare endpoint, so it measures real single-stream throughput — which is usually what matters for a single download or video stream anyway.
Does Wi-Fi vs Ethernet affect the result here?
Yes, often dramatically. Wi-Fi adds variable latency and throughput depending on signal, congestion, and channel. If you want the true line speed, run the test on a wired connection. If you want what your laptop sees, test where you usually work.
Troubleshooting
- The result is much lower than Ookla or fast.com
Expected. This is a single-stream download from one Cloudflare endpoint; the big speed tests open many parallel streams to multiple servers and report the peak. Use this for a ballpark, and one of those for a headline figure.
- The speed varies wildly between runs
Something else is sharing the line — another device streaming, a background update, or Wi-Fi interference. Run it two or three times with everything else idle, and on Ethernet if you can, for a number you can trust.
- Wi-Fi shows much slower than my broadband plan
The bottleneck is often the wireless hop, not the ISP. Distance from the router, walls, and 2.4 GHz congestion all cut throughput. Test next to the router or plug in with a cable to separate the line speed from the Wi-Fi.
- The test won't start or times out
A corporate proxy, a VPN, or an aggressive ad-blocker can block the Cloudflare speed endpoint. Try again with the VPN off or the extension paused, or on a different network.