WebSocket 1002 Protocol Error vs 1009 Message Too Big
Both WebSocket 1002 (Protocol Error) and 1009 (Message Too Big) belong to the WebSocket Close Codes category. 1002 indicates that an endpoint is terminating the connection because it received data that violates the WebSocket protocol specification. Meanwhile, 1009 means that an endpoint is terminating the connection because it received a message that is too large for it to process.
Descripción
An endpoint is terminating the connection because it received data that violates the WebSocket protocol specification.
Cuándo lo verás
The WebSocket frame format is invalid — a malformed header, incorrect masking, or a reserved opcode was used. This usually indicates a broken client or proxy.
Cómo solucionarlo
Check that both client and server strictly follow RFC 6455 framing rules. Inspect intermediary proxies that may be corrupting WebSocket frames.
Descripción
An endpoint is terminating the connection because it received a message that is too large for it to process.
Cuándo lo verás
The message payload exceeded the server's configured maximum frame or message size limit. Common when uploading large files or sending huge JSON payloads over WebSocket.
Cómo solucionarlo
Reduce the message size by chunking large payloads into smaller frames. Alternatively, increase the server's max message size configuration if the large payload is expected.
Diferencias clave
WebSocket 1002: An endpoint is terminating the connection because it received data that violates the WebSocket protocol specification.
WebSocket 1009: An endpoint is terminating the connection because it received a message that is too large for it to process.
You encounter 1002 when the WebSocket frame format is invalid — a malformed header, incorrect masking, or a reserved opcode was used. This usually indicates a broken client or proxy.
You encounter 1009 when the message payload exceeded the server's configured maximum frame or message size limit. Common when uploading large files or sending huge JSON payloads over WebSocket.
Cuándo usar cada uno
For 1002 (Protocol Error): Check that both client and server strictly follow RFC 6455 framing rules. Inspect intermediary proxies that may be corrupting WebSocket frames. For 1009 (Message Too Big): Reduce the message size by chunking large payloads into smaller frames. Alternatively, increase the server's max message size configuration if the large payload is expected.