--- layout: default title: uppercase_string parent: Processors grand_parent: Pipelines nav_order: 125 --- # uppercase_string The `uppercase_string` processor converts an entire string to uppercase and is a [mutate string](https://github.com/opensearch-project/data-prepper/tree/main/data-prepper-plugins/mutate-string-processors#mutate-string-processors) processor. The following table describes the option you can use to configure the `uppercase_string` processor. Option | Required | Type | Description :--- | :--- | :--- | :--- with_keys | Yes | List | A list of keys to convert to uppercase.