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Pagination in Apollo Client

Overview


GraphQL enables you to fetch exactly the fields you need from your graph, with no unnecessary overhead. This helps keep network responses small and fast.

However, GraphQL doesn't automatically guarantee small responses. This is especially apparent when you query a field that contains a list. A list can contain infinitely many elements, which can result in an enormous response from a seemingly small query like this one:

query GetBookTitles {
  books {
    title
  }
}

If your graph includes thousands or millions of books, this query probably returns much more data than you need. To resolve this issue, GraphQL servers can paginate their list fields.

When a client queries a paginated list field, the server returns only a portion (or "page") of the list's elements. The client's query includes arguments that indicate which page the server should return:

Client appGraphQL serverquery GetBookTitles(offset=0 limit=20)Returns the first 20 list elementsquery GetBookTitles(offset=20 limit=10)Returns the next 10 list elementsClient appGraphQL server

This diagram shows offset-based pagination, in which a client requests a page based on an absolute index in the list (offset) and the maximum number of elements to return (limit).

There are many different pagination strategies a server can use for a particular list field: offset-based, cursor-based, page-number-based, forwards, backwards, and so on. Each strategy requires a slightly different set of arguments. Because these strategies can each be useful in different situations, neither Apollo nor the GraphQL specification prescribes a canonical pagination strategy.

The Apollo Client approach

Instead of recommending a particular pagination strategy, Apollo Client provides flexible cache APIs that help you merge results from a paginated list field, regardless of which pagination strategy your GraphQL server uses. And because you can represent these custom pagination strategies with stateless functions, you can reuse a single function for every list field that uses the same strategy.

Ready to start paginating? Start by learning about the Core pagination API.

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