Postman
Postman supports GraphQL requests with built-in tools or raw POST requests, using application/json content type for queries and variables.
Postman has built-in support for GraphQL. You can make requests selecting GraphQL for the body type. There are two fields, QUERY and GRAPHQL VARIABLES where you can provide the query and variables.
You can achieve the same making a raw POST request, with the content type set to application/json and the body with the form explained in the beginning of this section.
Tip
You can learn more about Postman from its official Learning center.