index.md

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title: Unknown command
slug: Web/WebDriver/Errors/UnknownCommand

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The unknown command error is a WebDriver error that occurs when the driver does not recognize the command/HTTP endpoint.

Examples

The /session/{session id}/foo endpoint does not exist, and will return an unknown command error with a 404 Not Found HTTP status code:

curl -i -d '{}' http://localhost:4444/session/foo

HTTP/1.1 404 Not Found
Connection: close
Content-Type: application/json; charset=utf-8
Cache-Control: no-cache
Content-Length: 113
Date: Fri, 30 Mar 2018 15:30:51 GMT

{"value":{"error":"unknown command","message":"POST /session/asd did not match a known command","stacktrace":""}}

See also

• List of WebDriver errors

• List of WebDriver commands