This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The downlink
read-only property of the NetworkInformation
interface returns the effective bandwidth estimate in megabits per second, rounded to the nearest multiple of 25 kilobits per seconds. This value is based on recently observed application layer throughput across recently active connections, excluding connections made to a private address space. In the absence of recent bandwidth measurement data, the attribute value is determined by the properties of the underlying connection technology.
Note that Chrome-based browsers do not conform to the specification, and arbitrarily cap the reported downlink at a maximum of 10 Mbps as an anti-fingerprinting measure. Similar caps exist for the reported latency.
Syntax
var downLink = NetworkInformation.downlink
Value
A double
.
Specifications
Specification | Status | Comment |
---|---|---|
Network Information API The definition of 'downlink' in that specification. |
Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
downlink | Chrome Full support 61 | Edge Full support 79 | Firefox No support No | IE No support No | Opera Full support 48 | Safari No support No | WebView Android Full support 50 | Chrome Android Full support 38 | Firefox Android ? | Opera Android Full support 45 | Safari iOS No support No | Samsung Internet Android Full support 3.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Experimental. Expect behavior to change in the future.
- Experimental. Expect behavior to change in the future.