Using REST and GraphQL in different parts of a single web app

I'm creating a web app and I'm wondering if it's possible to create it using both REST and GraphQl. I don't mean I wan't to wrap REST in graphql. It is a web app with a variety of functionalities and graphql would be best suited towards the blog portion of the app but we've already constructed the rest of it using REST. Would it be possible/bad practice to use them for the respective parts of the app?