diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index d8356938fa..71c94e0fdc 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -123,6 +123,7 @@ set(SOURCES
     Dump.cpp
     Encoding/TextDecoder.cpp
     Encoding/TextEncoder.cpp
+    Fetch/BodyInit.cpp
     Fetch/Headers.cpp
     Fetch/HeadersIterator.cpp
     Fetch/Infrastructure/HTTP.cpp
diff --git a/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp b/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp
new file mode 100644
index 0000000000..20eda60e52
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Fetch/BodyInit.cpp
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2022, Kenneth Myhra <kennethmyhra@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/IDLAbstractOperations.h>
+#include <LibWeb/Fetch/BodyInit.h>
+#include <LibWeb/Fetch/Infrastructure/HTTP/Bodies.h>
+#include <LibWeb/HTML/Window.h>
+#include <LibWeb/URL/URLSearchParams.h>
+
+namespace Web::Fetch {
+
+// https://fetch.spec.whatwg.org/#concept-bodyinit-extract
+// FIXME: The parameter 'body_init' should be 'typedef (ReadableStream or XMLHttpRequestBodyInit) BodyInit'. For now we just let it be 'XMLHttpRequestBodyInit'.
+ErrorOr<Infrastructure::BodyWithType> extract_body(JS::Realm& realm, XMLHttpRequestBodyInit const& body_init)
+{
+    auto& window = verify_cast<HTML::Window>(realm.global_object());
+
+    // FIXME: 1. Let stream be object if object is a ReadableStream object. Otherwise, let stream be a new ReadableStream, and set up stream.
+    auto* stream = realm.heap().allocate<Streams::ReadableStream>(realm, window);
+    // FIXME: 2. Let action be null.
+    // 3. Let source be null.
+    Infrastructure::Body::SourceType source {};
+    // 4. Let length be null.
+    Optional<u64> length {};
+    // 5. Let type be null.
+    Optional<ByteBuffer> type {};
+
+    // 6. Switch on object.
+    // FIXME: Still need to support BufferSource and FormData
+    TRY(body_init.visit(
+        [&](JS::Handle<FileAPI::Blob> const& blob) -> ErrorOr<void> {
+            // FIXME: Set action to this step: read object.
+            // Set source to object.
+            source = blob;
+            // Set length to object’s size.
+            length = blob->size();
+            // If object’s type attribute is not the empty byte sequence, set type to its value.
+            if (!blob->type().is_empty())
+                type = blob->type().to_byte_buffer();
+            return {};
+        },
+        [&](JS::Handle<JS::Object> const& buffer_source) -> ErrorOr<void> {
+            // Set source to a copy of the bytes held by object.
+            source = TRY(Bindings::IDL::get_buffer_source_copy(*buffer_source.cell()));
+            return {};
+        },
+        [&](JS::Handle<URL::URLSearchParams> const& url_search_params) -> ErrorOr<void> {
+            // Set source to the result of running the application/x-www-form-urlencoded serializer with object’s list.
+            source = url_search_params->to_string().to_byte_buffer();
+            // Set type to `application/x-www-form-urlencoded;charset=UTF-8`.
+            type = TRY(ByteBuffer::copy("application/x-www-form-urlencoded;charset=UTF-8"sv.bytes()));
+            return {};
+        },
+        [&](String const& scalar_value_string) -> ErrorOr<void> {
+            // NOTE: AK::String is always UTF-8.
+            // Set source to the UTF-8 encoding of object.
+            source = scalar_value_string.to_byte_buffer();
+            // Set type to `text/plain;charset=UTF-8`.
+            type = TRY(ByteBuffer::copy("text/plain;charset=UTF-8"sv.bytes()));
+            return {};
+        }));
+
+    // FIXME: 7. If source is a byte sequence, then set action to a step that returns source and length to source’s length.
+    // FIXME: 8. If action is non-null, then run these steps in in parallel:
+
+    // 9. Let body be a body whose stream is stream, source is source, and length is length.
+    auto body = Infrastructure::Body { JS::make_handle(stream), move(source), move(length) };
+    // 10. Return (body, type).
+    return Infrastructure::BodyWithType { .body = move(body), .type = move(type) };
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/Fetch/BodyInit.h b/Userland/Libraries/LibWeb/Fetch/BodyInit.h
index e8ce881f50..24dc2f244c 100644
--- a/Userland/Libraries/LibWeb/Fetch/BodyInit.h
+++ b/Userland/Libraries/LibWeb/Fetch/BodyInit.h
@@ -16,4 +16,6 @@ namespace Web::Fetch {
 // https://fetch.spec.whatwg.org/#typedefdef-xmlhttprequestbodyinit
 using XMLHttpRequestBodyInit = Variant<JS::Handle<FileAPI::Blob>, JS::Handle<JS::Object>, JS::Handle<URL::URLSearchParams>, String>;
 
+ErrorOr<Infrastructure::BodyWithType> extract_body(JS::Realm&, XMLHttpRequestBodyInit const&);
+
 }
diff --git a/Userland/Libraries/LibWeb/Forward.h b/Userland/Libraries/LibWeb/Forward.h
index 94fde4f6cd..2ad2adad09 100644
--- a/Userland/Libraries/LibWeb/Forward.h
+++ b/Userland/Libraries/LibWeb/Forward.h
@@ -189,6 +189,7 @@ class HeadersIterator;
 
 namespace Web::Fetch::Infrastructure {
 class Body;
+struct BodyWithType;
 struct Header;
 class HeaderList;
 class Request;
diff --git a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
index d67b89fb5c..31cd8da00e 100644
--- a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
+++ b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
@@ -16,7 +16,6 @@
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibTextCodec/Decoder.h>
-#include <LibWeb/Bindings/IDLAbstractOperations.h>
 #include <LibWeb/Bindings/XMLHttpRequestPrototype.h>
 #include <LibWeb/DOM/DOMException.h>
 #include <LibWeb/DOM/Document.h>
@@ -24,6 +23,7 @@
 #include <LibWeb/DOM/EventDispatcher.h>
 #include <LibWeb/DOM/ExceptionOr.h>
 #include <LibWeb/DOM/IDLEventListener.h>
+#include <LibWeb/Fetch/BodyInit.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Bodies.h>
 #include <LibWeb/Fetch/Infrastructure/HTTP/Methods.h>
@@ -268,66 +268,6 @@ Optional<StringView> XMLHttpRequest::get_final_encoding() const
     return encoding;
 }
 
-// https://fetch.spec.whatwg.org/#concept-bodyinit-extract
-// FIXME: The parameter 'body_init' should be 'typedef (ReadableStream or XMLHttpRequestBodyInit) BodyInit'. For now we just let it be 'XMLHttpRequestBodyInit'.
-static ErrorOr<Fetch::Infrastructure::BodyWithType> extract_body(JS::Realm& realm, Fetch::XMLHttpRequestBodyInit const& body_init)
-{
-    auto& window = verify_cast<HTML::Window>(realm.global_object());
-
-    // FIXME: 1. Let stream be object if object is a ReadableStream object. Otherwise, let stream be a new ReadableStream, and set up stream.
-    auto* stream = realm.heap().allocate<Streams::ReadableStream>(realm, window);
-    // FIXME: 2. Let action be null.
-    // 3. Let source be null.
-    Fetch::Infrastructure::Body::SourceType source {};
-    // 4. Let length be null.
-    Optional<u64> length {};
-    // 5. Let type be null.
-    Optional<ByteBuffer> type {};
-
-    // 6. Switch on object.
-    // FIXME: Still need to support BufferSource and FormData
-    TRY(body_init.visit(
-        [&](JS::Handle<FileAPI::Blob> const& blob) -> ErrorOr<void> {
-            // FIXME: Set action to this step: read object.
-            // Set source to object.
-            source = blob;
-            // Set length to object’s size.
-            length = blob->size();
-            // If object’s type attribute is not the empty byte sequence, set type to its value.
-            if (!blob->type().is_empty())
-                type = blob->type().to_byte_buffer();
-            return {};
-        },
-        [&](JS::Handle<JS::Object> const& buffer_source) -> ErrorOr<void> {
-            // Set source to a copy of the bytes held by object.
-            source = TRY(Bindings::IDL::get_buffer_source_copy(*buffer_source.cell()));
-            return {};
-        },
-        [&](JS::Handle<URL::URLSearchParams> const& url_search_params) -> ErrorOr<void> {
-            // Set source to the result of running the application/x-www-form-urlencoded serializer with object’s list.
-            source = url_search_params->to_string().to_byte_buffer();
-            // Set type to `application/x-www-form-urlencoded;charset=UTF-8`.
-            type = TRY(ByteBuffer::copy("application/x-www-form-urlencoded;charset=UTF-8"sv.bytes()));
-            return {};
-        },
-        [&](String const& scalar_value_string) -> ErrorOr<void> {
-            // NOTE: AK::String is always UTF-8.
-            // Set source to the UTF-8 encoding of object.
-            source = scalar_value_string.to_byte_buffer();
-            // Set type to `text/plain;charset=UTF-8`.
-            type = TRY(ByteBuffer::copy("text/plain;charset=UTF-8"sv.bytes()));
-            return {};
-        }));
-
-    // FIXME: 7. If source is a byte sequence, then set action to a step that returns source and length to source’s length.
-    // FIXME: 8. If action is non-null, then run these steps in in parallel:
-
-    // 9. Let body be a body whose stream is stream, source is source, and length is length.
-    auto body = Fetch::Infrastructure::Body { JS::make_handle(stream), move(source), move(length) };
-    // 10. Return (body, type).
-    return Fetch::Infrastructure::BodyWithType { .body = move(body), .type = move(type) };
-}
-
 // https://xhr.spec.whatwg.org/#dom-xmlhttprequest-setrequestheader
 DOM::ExceptionOr<void> XMLHttpRequest::set_request_header(String const& name_string, String const& value_string)
 {
@@ -470,7 +410,7 @@ DOM::ExceptionOr<void> XMLHttpRequest::send(Optional<Fetch::XMLHttpRequestBodyIn
     if (m_method.is_one_of("GET"sv, "HEAD"sv))
         body = {};
 
-    auto body_with_type = body.has_value() ? TRY_OR_RETURN_OOM(global_object(), extract_body(realm, body.value())) : Optional<Fetch::Infrastructure::BodyWithType> {};
+    auto body_with_type = body.has_value() ? TRY_OR_RETURN_OOM(global_object(), Fetch::extract_body(realm, body.value())) : Optional<Fetch::Infrastructure::BodyWithType> {};
 
     AK::URL request_url = m_window->associated_document().parse_url(m_url.to_string());
     dbgln("XHR send from {} to {}", m_window->associated_document().url(), request_url);