diff --git a/CHANGELOG.md b/CHANGELOG.md
index ab593c1b1c..0c18b47f0d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -118,6 +118,8 @@
 	  - 猫耳のアバター内部部分をぼかしでマスク表示してより猫耳っぽく見えるように
 	- 「UIのアニメーションを減らす」 (`reduceAnimation`) で猫耳を撫でられなくなります
 - Add Minimizing ("folding") of windows
+- 「データセーバー」モードを追加
+- 非NSFWメディアが隠れている際にも「閲覧注意」が出てしまう問題を修正
 
 ### Server
 - PostgreSQLのレプリケーション対応
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 5f5bcfd879..b991ec2e9b 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -271,6 +271,7 @@ home: "ホーム"
 remoteUserCaution: "リモートユーザーのため、情報が不完全です。"
 activity: "アクティビティ"
 images: "画像"
+image: "画像"
 birthday: "誕生日"
 yearsOld: "{age}歳"
 registeredDate: "登録日"
@@ -990,6 +991,9 @@ enableChartsForFederatedInstances: "リモートサーバーのチャートを
 showClipButtonInNoteFooter: "ノートのアクションにクリップを追加"
 largeNoteReactions: "ノートのリアクションを大きく表示"
 noteIdOrUrl: "ノートIDまたはURL"
+video: "動画"
+videos: "動画"
+dataSaver: "データセーバー"
 accountMigration: "アカウントの引っ越し"
 accountMoved: "このユーザーは新しいアカウントに引っ越しました："
 forceShowAds: "常に広告を表示する"
diff --git a/packages/frontend/src/components/MkImgWithBlurhash.vue b/packages/frontend/src/components/MkImgWithBlurhash.vue
index 944c76d7dc..9b3dbf8618 100644
--- a/packages/frontend/src/components/MkImgWithBlurhash.vue
+++ b/packages/frontend/src/components/MkImgWithBlurhash.vue
@@ -1,7 +1,7 @@
 <template>
 <div :class="[$style.root, { [$style.cover]: cover }]" :title="title">
-	<canvas v-if="!loaded" ref="canvas" :class="$style.canvas" :width="size" :height="size" :title="title"/>
-	<img v-if="src" :class="$style.img" :src="src" :title="title" :alt="alt" @load="onLoad"/>
+	<canvas v-if="!loaded || forceBlurhash" ref="canvas" :class="$style.canvas" :width="size" :height="size" :title="title"/>
+	<img v-if="src && !forceBlurhash" :class="$style.img" :src="src" :title="title" :alt="alt" @load="onLoad"/>
 </div>
 </template>
 
@@ -12,16 +12,18 @@ import { decode } from 'blurhash';
 const props = withDefaults(defineProps<{
 	src?: string | null;
 	hash?: string;
-	alt?: string;
+	alt?: string | null;
 	title?: string | null;
 	size?: number;
 	cover?: boolean;
+	forceBlurhash?: boolean;
 }>(), {
 	src: null,
 	alt: '',
 	title: null,
 	size: 64,
 	cover: true,
+	forceBlurhash: false,
 });
 
 const canvas = $shallowRef<HTMLCanvasElement>();
diff --git a/packages/frontend/src/components/MkMediaImage.vue b/packages/frontend/src/components/MkMediaImage.vue
index a4065dcd07..8d0877ef61 100644
--- a/packages/frontend/src/components/MkMediaImage.vue
+++ b/packages/frontend/src/components/MkMediaImage.vue
@@ -1,9 +1,10 @@
 <template>
 <div v-if="hide" :class="$style.hidden" @click="hide = false">
-	<ImgWithBlurhash style="filter: brightness(0.5);" :hash="image.blurhash" :title="image.comment" :alt="image.comment"/>
+	<ImgWithBlurhash style="filter: brightness(0.5);" :hash="image.blurhash" :title="image.comment" :alt="image.comment" :force-blurhash="defaultStore.state.enableDataSaverMode" />
 	<div :class="$style.hiddenText">
 		<div :class="$style.hiddenTextWrapper">
-			<b style="display: block;"><i class="ti ti-alert-triangle"></i> {{ i18n.ts.sensitive }}</b>
+			<b v-if="image.isSensitive" style="display: block;"><i class="ti ti-alert-triangle"></i> {{ i18n.ts.sensitive }}{{ defaultStore.state.enableDataSaverMode ? ` (${i18n.ts.image}${image.size ? ' ' + bytes(image.size) : ''})` : '' }}</b>
+			<b v-else style="display: block;"><i class="ti ti-photo"></i> {{ defaultStore.state.enableDataSaverMode && image.size ? bytes(image.size) : i18n.ts.image }}</b>
 			<span style="display: block;">{{ i18n.ts.clickToShow }}</span>
 		</div>
 	</div>
@@ -28,6 +29,7 @@
 import { watch } from 'vue';
 import * as misskey from 'misskey-js';
 import { getStaticImageUrl } from '@/scripts/media-proxy';
+import bytes from '@/filters/bytes';
 import ImgWithBlurhash from '@/components/MkImgWithBlurhash.vue';
 import { defaultStore } from '@/store';
 import { i18n } from '@/i18n';
@@ -38,7 +40,7 @@ const props = defineProps<{
 }>();
 
 let hide = $ref(true);
-let darkMode = $ref(defaultStore.state.darkMode);
+let darkMode: boolean = $ref(defaultStore.state.darkMode);
 
 const url = (props.raw || defaultStore.state.loadRawImages)
 	? props.image.url
@@ -48,7 +50,7 @@ const url = (props.raw || defaultStore.state.loadRawImages)
 
 // Plugin:register_note_view_interruptor を使って書き換えられる可能性があるためwatchする
 watch(() => props.image, () => {
-	hide = (defaultStore.state.nsfw === 'force') ? true : props.image.isSensitive && (defaultStore.state.nsfw !== 'ignore');
+	hide = (defaultStore.state.nsfw === 'force' || defaultStore.state.enableDataSaverMode) ? true : (props.image.isSensitive && defaultStore.state.nsfw !== 'ignore');
 }, {
 	deep: true,
 	immediate: true,
diff --git a/packages/frontend/src/components/MkMediaVideo.vue b/packages/frontend/src/components/MkMediaVideo.vue
index e02a7af09e..a4b76300e6 100644
--- a/packages/frontend/src/components/MkMediaVideo.vue
+++ b/packages/frontend/src/components/MkMediaVideo.vue
@@ -1,7 +1,9 @@
 <template>
 <div v-if="hide" class="icozogqfvdetwohsdglrbswgrejoxbdj" @click="hide = false">
+	<!-- 【注意】dataSaverMode が有効になっている際には、hide が false になるまでサムネイルや動画を読み込まないようにすること -->
 	<div>
-		<b><i class="ti ti-alert-triangle"></i> {{ i18n.ts.sensitive }}</b>
+		<b v-if="video.isSensitive"><i class="ti ti-alert-triangle"></i> {{ i18n.ts.sensitive }}{{ defaultStore.state.enableDataSaverMode ? ` (${i18n.ts.video}${video.size ? ' ' + bytes(video.size) : ''})` : '' }}</b>
+		<b v-else><i class="ti ti-movie"></i> {{ defaultStore.state.enableDataSaverMode && video.size ? bytes(video.size) : i18n.ts.video }}</b>
 		<span>{{ i18n.ts.clickToShow }}</span>
 	</div>
 </div>
@@ -25,6 +27,7 @@
 <script lang="ts" setup>
 import { ref } from 'vue';
 import * as misskey from 'misskey-js';
+import bytes from '@/filters/bytes';
 import VuePlyr from 'vue-plyr';
 import { defaultStore } from '@/store';
 import 'vue-plyr/dist/vue-plyr.css';
@@ -34,7 +37,7 @@ const props = defineProps<{
 	video: misskey.entities.DriveFile;
 }>();
 
-const hide = ref((defaultStore.state.nsfw === 'force') ? true : props.video.isSensitive && (defaultStore.state.nsfw !== 'ignore'));
+const hide = ref((defaultStore.state.nsfw === 'force' || defaultStore.state.enableDataSaverMode) ? true : (props.video.isSensitive && defaultStore.state.nsfw !== 'ignore'));
 </script>
 
 <style lang="scss" scoped>
diff --git a/packages/frontend/src/pages/settings/general.vue b/packages/frontend/src/pages/settings/general.vue
index 904fd3f952..29657c04ac 100644
--- a/packages/frontend/src/pages/settings/general.vue
+++ b/packages/frontend/src/pages/settings/general.vue
@@ -62,6 +62,7 @@
 				<MkSwitch v-model="useSystemFont">{{ i18n.ts.useSystemFont }}</MkSwitch>
 				<MkSwitch v-model="disableDrawer">{{ i18n.ts.disableDrawer }}</MkSwitch>
 				<MkSwitch v-model="forceShowAds">{{ i18n.ts.forceShowAds }}</MkSwitch>
+				<MkSwitch v-model="enableDataSaverMode">{{ i18n.ts.dataSaver }}</MkSwitch>
 			</div>
 			<div>
 				<MkRadios v-model="emojiStyle">
@@ -160,6 +161,7 @@ const disableDrawer = computed(defaultStore.makeGetterSetter('disableDrawer'));
 const disableShowingAnimatedImages = computed(defaultStore.makeGetterSetter('disableShowingAnimatedImages'));
 const forceShowAds = computed(defaultStore.makeGetterSetter('forceShowAds'));
 const loadRawImages = computed(defaultStore.makeGetterSetter('loadRawImages'));
+const enableDataSaverMode = computed(defaultStore.makeGetterSetter('enableDataSaverMode'));
 const imageNewTab = computed(defaultStore.makeGetterSetter('imageNewTab'));
 const nsfw = computed(defaultStore.makeGetterSetter('nsfw'));
 const showFixedPostForm = computed(defaultStore.makeGetterSetter('showFixedPostForm'));
diff --git a/packages/frontend/src/store.ts b/packages/frontend/src/store.ts
index a935093240..a8e01b9385 100644
--- a/packages/frontend/src/store.ts
+++ b/packages/frontend/src/store.ts
@@ -182,6 +182,10 @@ export const defaultStore = markRaw(new Storage('base', {
 		where: 'device',
 		default: false,
 	},
+	enableDataSaverMode: {
+		where: 'device',
+		default: false,
+	},
 	disableShowingAnimatedImages: {
 		where: 'device',
 		default: matchMedia('(prefers-reduced-motion)').matches,