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Effective connection type - Glossary | MDN
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Effective connection type
Effective connection type (ECT) refers to the measured network performance, returning a cellular connection type, like 3G, even if the actual connection is tethered broadband or Wi-Fi, based on the time between the browser requesting a page and effective type of the connection.
The values of slow-2g, 2g, 3g, and 4g are determined using observed round-trip times and downlink values.
| ECT | Minimum RTT | Maximum downlink | Explanation |
|---|---|---|---|
slow-2g |
2000ms | 50 Kbps | The network is suited for small transfers only such as text-only pages. |
2g |
1400ms | 70 Kbps | The network is suited for transfers of small images. |
3g |
270ms | 700 Kbps | The network is suited for transfers of large assets such as high resolution images, audio, and SD video. |
4g |
0ms | ∞ | The network is suited for HD video, real-time video, etc. |
effectiveType is a property of the Network Information API, exposed to JavaScript via the navigator.connection object. To see your effective connection type, open the console of the developer tools of a supporting browser and enter the following:
js
navigator.connection.effectiveType;