--- layout: default title: uppercase_string parent: Processors grand_parent: Configuring Data Prepper nav_order: 45 --- # uppercase_string ## Overview Converts a string to its uppercase counterpart. `uppercase_string` is part of [mutate string](https://github.com/opensearch-project/data-prepper/tree/main/data-prepper-plugins/mutate-string-processors#mutate-string-processors) processors. Option | Required | Type | Description :--- | :--- | :--- | :--- with_keys | Yes | List | A list of keys to convert to uppercase.