fetch()

The global fetch() method starts the process of fetching a resource from the network, returning a promise which is fulfilled once the response is available.

The promise resolves to the Response object representing the response to your request.

A fetch() promise only rejects when a network error is encountered (which is usually when there's a permissions issue or similar). A fetch() promise does not reject on HTTP errors (404, etc.). Instead, a then() handler must check the Response.ok and/or Response.status properties.

Note: The fetch() method's parameters are identical to those of the Request() constructor.

Syntax

fetch(resource)
fetch(resource, options)

Parameters

• resource

  • : This defines the resource that you wish to fetch. This can either be:

    • A string or any other object with a "toString" method.
    • A Request object.

• options optional

  • : An object containing any custom settings that you want to apply to the request. The possible options are:

    • method
      • : The request method, e.g., GET, POST.
    • headers
      • : Any headers you want to add to your request, contained within a Headers object or an object literal with String values.
    • body
      • : Any body that you want to add to your request: this can be an ArrayBuffer, a TypedArray, a DataView, a URLSearchParams, string object or literal, or a ReadableStream object.
    • backend Fastly-specific
      • Fastly-specific
    • cacheOverride Fastly-specific
    • cacheKey Fastly-specific

Return value

A Promise that resolves to a Response object.