The code
read-only property of the CloseEvent
interface returns a WebSocket connection close code indicating the reason the server gave for closing the connection.
The code
read-only property of the CloseEvent
interface returns a WebSocket connection close code indicating the reason the server gave for closing the connection.
An integer WebSocket connection close code in the range 1000
- 4999
, indicating the reason the server gave for closing the connection.
Status code | Meaning | Description |
---|---|---|
0 –999
| Not used. | |
1000 | Normal Closure | The connection successfully completed the purpose for which it was created. |
1001 | Going Away | The endpoint is going away, either because of a server failure or because the browser is navigating away from the page that opened the connection. |
1002 | Protocol error | The endpoint is terminating the connection due to a protocol error. |
1003 | Unsupported Data | The connection is being terminated because the endpoint received data of a type it cannot accept. (For example, a text-only endpoint received binary data.) |
1004 | Reserved | Reserved. A meaning might be defined in the future. |
1005 | No Status Rcvd | Reserved. Indicates that no status code was provided even though one was expected. |
1006 | Abnormal Closure | Reserved. Indicates that a connection was closed abnormally (that is, with no close frame being sent) when a status code is expected. |
1007 | Invalid frame payload data | The endpoint is terminating the connection because a message was received that contained inconsistent data (e.g., non-UTF-8 data within a text message). |
1008 | Policy Violation | The endpoint is terminating the connection because it received a message that violates its policy. This is a generic status code, used when codes 1003 and 1009 are not suitable. |
1009 | Message Too Big | The endpoint is terminating the connection because a data frame was received that is too large. |
1010 | Mandatory Ext. | The client is terminating the connection because it expected the server to negotiate one or more extension, but the server didn't. |
1011 | Internal Error | The server is terminating the connection because it encountered an unexpected condition that prevented it from fulfilling the request. |
1012 | Service Restart | The server is terminating the connection because it is restarting. |
1013 | Try Again Later | The server is terminating the connection due to a temporary condition, e.g. it is overloaded and is casting off some of its clients. |
1014 | Bad Gateway | The server was acting as a gateway or proxy and received an invalid response from the upstream server. This is similar to 502 HTTP Status Code. |
1015 | TLS handshake | Reserved. Indicates that the connection was closed due to a failure to perform a TLS handshake (e.g., the server certificate can't be verified). |
1016 –2999
| For definition by future revisions of the WebSocket Protocol specification, and for definition by extension specifications. | |
3000 –3999
| For use by libraries, frameworks, and applications. These status codes are registered directly with IANA. The interpretation of these codes is undefined by the WebSocket protocol. | |
4000 –4999
| For private use, and thus can't be registered. Such codes can be used by prior agreements between WebSocket applications. The interpretation of these codes is undefined by the WebSocket protocol. |
The following example prints the value of code
to the console.
js
WebSocket.onclose = (event) => { console.log(event.code); };
Specification |
---|
WebSockets Standard # ref-for-dom-closeevent-code② |
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
code |
15 | 12 | 8 | 10 | 12.1 | 6 | 4.4 | 18 | 8 | 12.1 | 6 | 1.0 |
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https://developer.mozilla.org/en-US/docs/Web/API/CloseEvent/code