WebTransportError: WebTransportError() constructor
Baseline
2026
Newly available
Since March 2026, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The WebTransportError() constructor creates a new WebTransportError object instance.
Syntax
new WebTransportError(init)
Parameters
initOptional-
An object containing the following properties:
message-
A string describing the error that has occurred.
streamErrorCode-
A number in the range 0-255 indicating the application protocol error code for this error.
Examples
A developer would not use this constructor manually. A new WebTransportError object is constructed when an error related to WebTransport occurs, for example a server error or network connection problem.
const url = "not-a-url";
async function initTransport(url) {
try {
// Initialize transport connection
const transport = new WebTransport(url);
// The connection can be used once ready fulfills
await transport.ready;
// …
} catch (error) {
const msg = `Transport initialization failed.
Reason: ${error.message}.
Source: ${error.source}.
Error code: ${error.streamErrorCode}.`;
console.log(msg);
}
}
Specifications
| Specification |
|---|
| WebTransport # dom-webtransporterror-webtransporterror |
Browser compatibility
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WebTransportError() constructor
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Legend
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- Full support
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- User must explicitly enable this feature.