How Speedhound measures
Exactly what the test does, how each number is calculated and where its limits are.
Test server
Every request goes to speed.cloudflare.com, which routes you to the nearest Cloudflare data center. The results panel names that data center. Speedhound runs no test servers of its own and stores nothing about your test.
The test, step by step
| Phase | What happens | Result |
|---|---|---|
| Idle ping | One warm-up request, then 20 tiny HTTPS requests one after another. A request that takes over 2 seconds counts as lost. | Ping is the median of the 20 times. Jitter is the average difference between consecutive times. Packet loss is the share that timed out. |
| Download | 8 seconds over 4 parallel connections, with file sizes growing from 1 MB to 100 MB. A ping request runs every 250 ms throughout. | Speed counts only the last 6 seconds, skipping the first 2 seconds of ramp-up. Loaded ping is the median of the pings sent during this phase. |
| Upload | 6 seconds over 3 parallel connections, with uploads growing from 1 MB to 10 MB, again with a ping every 250 ms. | Speed counts only the last 4.5 seconds. Loaded ping is the median during this phase. |
How the bufferbloat grade is calculated
Added latency = the higher of the two loaded pings (download or upload) − idle ping, never below zero. That number maps to a grade:
| Grade | Added latency |
|---|---|
| A+ | Under 5 ms |
| A | 5 to under 30 ms |
| B | 30 to under 60 ms |
| C | 60 to under 200 ms |
| D | 200 to under 400 ms |
| F | 400 ms or more |
The grade uses medians, so it shows typical delay under load. Short spikes that hit only a few pings do not move it much. See the bufferbloat test for what each grade feels like and how to fix a bad one.
How the verdicts are decided
| Verdict | Good | Borderline |
|---|---|---|
| 4K streaming | 25 Mbps or more down | 15 Mbps or more down |
| Video calls | 3+ Mbps up, ping up to 100 ms, jitter up to 30 ms | 1.5+ Mbps up and ping up to 150 ms |
| Online gaming | Ping up to 50 ms, jitter up to 15 ms and a bufferbloat grade of B or better | Ping up to 100 ms and jitter up to 30 ms |
| Cloud backup | 50 Mbps or more up | 10 Mbps or more up |
Anything below Borderline is Poor. Packet loss above 2% caps video calls at Borderline; above 1% does the same for gaming.
Known limits
- The test is short (about 20 seconds). Cable connections that burst fast for the first seconds and then slow down can read higher than a long download would.
- Ping is timed over HTTPS, not ICMP, so it reads slightly higher than a command-line ping.
- Packet loss is estimated from 20 requests, so the smallest non-zero value is 5%. It is a rough signal, not a precise count.
- Download and upload are tested separately, not at the same time.
- Your browser, Wi-Fi, VPN, other devices and background apps all affect the result.
Questions
Why is my result different from Speedtest.net or fast.com?
Each test uses different servers, a different number of connections and a different test length. Speedtest.net often picks a server inside your ISP's own network, which can read higher than traffic to the wider internet. Speedhound tests against Cloudflare's nearest data center, the same kind of path most websites use. Run both a few times; differences of 10 to 20% are normal.
Why does Speedhound measure ping over HTTP instead of ICMP?
Browsers cannot send ICMP ping packets. Speedhound times a tiny HTTPS request instead, so its ping includes a little request overhead and usually reads a few milliseconds higher than a command-line ping.
Does Speedhound store my results?
No. The test runs in your browser and the numbers stay there. If you share a result, the numbers are written into the link itself, so nothing is saved on a server.
More from Speedhound
- Speed testDownload, upload, ping, jitter and bufferbloat in 20 seconds.
- Bufferbloat testSee how much lag your connection adds under load.
- Download time calculatorHow long a file takes at your speed.
- Good internet speedHow many Mbps you need for your household.
- Good pingWhat ping, jitter and packet loss numbers mean.