diff --git a/src/helpers/contents.ts b/src/helpers/contents.ts
new file mode 100644
index 0000000..00967b9
--- /dev/null
+++ b/src/helpers/contents.ts
@@ -0,0 +1,31 @@
+import { ContentWithTranslations, Immutable } from "./types";
+
+type Group = Immutable<
+  NonNullable<
+    NonNullable<
+      NonNullable<
+        NonNullable<ContentWithTranslations["group"]>["data"]
+      >["attributes"]
+    >["contents"]
+  >["data"]
+>;
+
+export function getPreviousContent(group: Group, currentSlug: string) {
+  for (let index = 0; index < group.length; index += 1) {
+    const content = group[index];
+    if (content.attributes?.slug === currentSlug && index > 0) {
+      return group[index - 1];
+    }
+  }
+  return undefined;
+}
+
+export function getNextContent(group: Group, currentSlug: string) {
+  for (let index = 0; index < group.length; index += 1) {
+    const content = group[index];
+    if (content.attributes?.slug === currentSlug && index < group.length - 1) {
+      return group[index + 1];
+    }
+  }
+  return undefined;
+}
diff --git a/src/pages/contents/[slug]/index.tsx b/src/pages/contents/[slug]/index.tsx
index 8590235..60504b8 100644
--- a/src/pages/contents/[slug]/index.tsx
+++ b/src/pages/contents/[slug]/index.tsx
@@ -15,6 +15,7 @@ import { ThumbnailHeader } from "components/ThumbnailHeader";
 import { ToolTip } from "components/ToolTip";
 import { AppStaticProps, getAppStaticProps } from "graphql/getAppStaticProps";
 import { getReadySdk } from "graphql/sdk";
+import { getNextContent, getPreviousContent } from "helpers/contents";
 import {
   prettyinlineTitle,
   prettyLanguage,
@@ -34,48 +35,6 @@ interface Props extends AppStaticProps {
   content: ContentWithTranslations;
 }
 
-function getPreviousContent(
-  group: Immutable<
-    NonNullable<
-      NonNullable<
-        NonNullable<
-          NonNullable<ContentWithTranslations["group"]>["data"]
-        >["attributes"]
-      >["contents"]
-    >["data"]
-  >,
-  currentSlug: string
-) {
-  for (let index = 0; index < group.length; index += 1) {
-    const content = group[index];
-    if (content.attributes?.slug === currentSlug && index > 0) {
-      return group[index - 1];
-    }
-  }
-  return undefined;
-}
-
-function getNextContent(
-  group: Immutable<
-    NonNullable<
-      NonNullable<
-        NonNullable<
-          NonNullable<ContentWithTranslations["group"]>["data"]
-        >["attributes"]
-      >["contents"]
-    >["data"]
-  >,
-  currentSlug: string
-) {
-  for (let index = 0; index < group.length; index += 1) {
-    const content = group[index];
-    if (content.attributes?.slug === currentSlug && index < group.length - 1) {
-      return group[index + 1];
-    }
-  }
-  return undefined;
-}
-
 export default function Content(props: Immutable<Props>): JSX.Element {
   const { langui, content, languages } = props;
   const isMobile = useMediaMobile();