# Environment Variables

WebdriverIO sets the following environment variables within every worker:

## `NODE_ENV`[​](#node_env "Direct link to node_env")

Set to `'test'` if it's not already set to something else.

## `WDIO_LOG_LEVEL`[​](#wdio_log_level "Direct link to wdio_log_level")

Can be set to values `trace`, `debug`, `info`, `warn`, `error`, `silent` to write logs with corresponding details. Has priority over the passed `logLevel` value.

## `WDIO_WORKER_ID`[​](#wdio_worker_id "Direct link to wdio_worker_id")

An unique id that helps identify the worker process. It has format of `{number}-{number}` where the first number identifies the capability and the second the spec file that capability is running, e.g. `0-5` indicates a worker the first running the 6th spec file for the first capability.