| 0 - 999 |
|
Yes |
No |
Unused |
| 1000 |
CLOSE_NORMAL |
No |
No |
Successful operation / regular socket shutdown |
| 1001 |
CLOSE_GOING_AWAY |
No |
No |
Client is leaving (browser tab closing) |
| 1002 |
CLOSE_PROTOCOL_ERROR |
Yes |
No |
Endpoint received a malformed frame |
| 1003 |
CLOSE_UNSUPPORTED |
Yes |
No |
Endpoint received an unsupported frame (e.g. binary-only endpoint received text frame) |
| 1004 |
|
Yes |
No |
Reserved |
| 1005 |
CLOSED_NO_STATUS |
Yes |
No |
Expected close status, received none |
| 1006 |
CLOSE_ABNORMAL |
Yes |
No |
No close code frame has been receieved |
| 1007 |
Unsupported payload |
Yes |
No |
Endpoint received inconsistent message (e.g. malformed UTF-8) |
| 1008 |
Policy violation |
No |
No |
Generic code used for situations other than 1003 and 1009 |
| 1009 |
CLOSE_TOO_LARGE |
No |
No |
Endpoint won’t process large frame |
| 1010 |
Mandatory extension |
No |
No |
Client wanted an extension which server did not negotiate |
| 1011 |
Server error |
No |
No |
Internal server error while operating |
| 1012 |
Service restart |
No |
No |
Server/service is restarting |
| 1013 |
Try again later |
No |
No |
Temporary server condition forced blocking client’s request |
| 1014 |
Bad gateway |
No |
No |
Server acting as gateway received an invalid response |
| 1015 |
TLS handshake fail |
Yes |
No |
Transport Layer Security handshake failure |
| 1016 - 1999 |
|
Yes |
No |
Reserved for later |
| 2000 - 2999 |
|
Yes |
Yes |
Reserved for websocket extensions |
| 3000 - 3999 |
|
No |
Yes |
Registered first come first serve at IANA |
| 4000 - 4999 |
|
No |
Yes |
Available for applications |