ErrLookup › websockets/ws
websockets/ws
Simple to use, blazing fast and thoroughly tested WebSocket client and server for Node.js · JavaScript · 20 source files
Analyzed at c791e707ea on 2026-08-06. 21 documented errors.
| Code / Message | Type | Severity | Tags |
|---|---|---|---|
| ws does not work in the browser. Browser clients must use… | exception | critical | browser, bundler, webpack, isomorphic, environment |
| Unexpected character at index | exception | error | websocket, protocol, parsing, header, rfc6455, sec-websocket-extensions |
| None of the extension offers can be accepted | exception | error | websocket, compression, permessage-deflate, negotiation, handshake, rfc7692 |
| Unexpected or invalid parameter "client_max_window_bits" | exception | error | websocket, compression, permessage-deflate, negotiation, handshake, client, rfc7692 |
| First argument must be a valid error code number | exception | error | websocket, close, status-code, protocol, rfc6455 |
| One and only one of the "port", "server", or "noServer"… | exception | critical | websocket-server, configuration, constructor, validation |
| server.handleUpgrade() was called more than once with the… | exception | critical | websocket-server, handleupgrade, configuration, multiple-servers, upgrade |
| The message must not be greater than 123 bytes | exception | error | websocket, close-frame, rfc6455, validation, control-frame |
| Unexpected end of input | exception | error | websocket, protocol, parsing, header, rfc6455, sec-websocket-extensions |
| Invalid URL | exception | error | websocket, client, url, validation, configuration |
| An invalid or duplicated subprotocol was specified | exception | error | websocket, client, subprotocol, validation, regex |
| Second argument must be a string or a Uint8Array | exception | error | websocket, close-frame, type-error, validation, typescript |
| WebSocket is not open: readyState 0 (CONNECTING) | exception | error | websocket, ping, readystate, connecting, lifecycle |
| Unknown parameter | exception | error | websocket, compression, permessage-deflate, negotiation, validation, rfc7692 |
| The server is operating in "noServer" mode | exception | error | websocket-server, noserver, configuration, api-misuse |
| Unsupported protocol version | exception | error | websocket, client, protocolversion, configuration, rfc6455 |
| The data size must not be greater than 125 bytes | exception | error | websocket, ping, control-frame, rfc6455, validation |
| Unexpected parameter "client_no_context_takeover" | exception | error | websocket, compression, permessage-deflate, negotiation, handshake, client |
| Parameter " " must have only a single value | exception | error | websocket, compression, permessage-deflate, negotiation, header, rfc7692 |
| Invalid value for parameter | exception | error | websocket, compression, permessage-deflate, negotiation, validation, rfc7692 |
| The " " subprotocol is duplicated | exception | warning | websocket, subprotocol, header-parsing, rfc6455, deduplication |