How this internet speed test works
When you press Start, your browser runs three measurements against the closest data centre of Cloudflare's global network, which has locations in hundreds of cities, so the test server is almost always near you:
- Ping and jitter: 20 tiny requests measure the round-trip time and how much it varies.
- Download: files of increasing size (100 KB up to 100 MB) are downloaded until each transfer takes long enough to saturate your connection. Your speed is the 90th percentile of those measurements, which filters out slow starts.
- Upload: the same approach in reverse, sending random data.
Everything runs in your browser; the results are not stored or sent to our server.
What is a good internet speed?
| Activity | Download | Upload | Ping |
|---|---|---|---|
| Web browsing and email | 5 Mbps | 1 Mbps | < 150 ms |
| HD video streaming (1080p) | 5–10 Mbps | — | — |
| 4K video streaming | 25 Mbps per stream | — | — |
| Video calls (HD) | 3–4 Mbps | 3–4 Mbps | < 100 ms |
| Online gaming | 10 Mbps | 3 Mbps | < 50 ms, low jitter |
| Working from home with cloud uploads | 50 Mbps | 10–20 Mbps | < 100 ms |
| Household with several 4K streams and gamers | 200+ Mbps | 20+ Mbps | < 50 ms |
Streaming figures follow the published recommendations of the major streaming services; requirements add up when several people use the connection at the same time. For latency, jitter and packet loss in more detail, try our ping and jitter test.
Why is my internet slower than my plan?
- Wi-Fi is the bottleneck. Distance, walls and interference often cut speeds in half. Test with an Ethernet cable to see what your line really delivers.
- Other devices are busy. Backups, game downloads and streams on other devices share the same connection.
- Old hardware. Routers, network cards and cables (Cat5 instead of Cat5e or better) can cap speeds.
- VPNs add encryption overhead and route traffic through a distant server.
- Peak-time congestion in your ISP's network, typically in the evening.
- Plans are "up to" speeds. Test several times at different hours before contacting your ISP.
Still slow? Work through our internet troubleshooter or read how to fix common internet connection problems.
Mbps vs MB/s
Internet speeds are measured in megabits per second (Mbps), but downloads in your browser usually show megabytes per second (MB/s). There are 8 bits in a byte, so a 100 Mbps connection downloads at most about 12.5 MB/s.
Frequently asked questions
Why do different speed tests give different results?
Each test uses different servers, methods and numbers of parallel connections, and your connection speed varies from minute to minute. Compare results from the same test over time.
Does the test measure my speed to every website?
No. It measures the speed between you and the nearest Cloudflare data centre. Websites hosted far away or on congested networks can be slower.
Is upload speed important?
Yes, for video calls, cloud backups, sending large files, live streaming and online gaming. Many cable and DSL plans have much lower upload than download speeds.
Should I test over Wi-Fi or cable?
Test over Ethernet to check your ISP's line, and over Wi-Fi to see what your devices really get. A big difference means it's time to improve your Wi-Fi.