Insomnia
Insomnia offers superior GraphQL support with schema fetching, autocomplete, and an interactive schema explorer for efficient API management.
Insomnia is an application that has many similarities with Postman, although it provides better support for working with GraphQL schemas.
You can use the schema button in the query window to fetch or refresh the schema and then you get auto complete suport in the query editor.
Insomnia allows you to explore the schema documentation by using the Show Documentation option from the schema button. This is shown in the following image:
The schema explorer can also be opened by hovering the cursor over any part of the query and then clickin on the links in the tooltip window.
The schema explorer allows you to navigate through the schema and understand its structure.
Tip
You can learn more about Insomnia from its official documentation. See Insomnia Docs.