diff --git a/packages/backend/src/server/web/views/info-card.pug b/packages/backend/src/server/web/views/info-card.pug
index 2a4954ec8b..d4bfbae3ba 100644
--- a/packages/backend/src/server/web/views/info-card.pug
+++ b/packages/backend/src/server/web/views/info-card.pug
@@ -43,7 +43,7 @@ html
 			}
 
 	body
-		a#a(href=`https://${host}` target="_blank")
+		a#a(href=`https://${host}` rel="noopener" target="_blank")
 			header#banner(style=`background-image: url(${meta.bannerUrl})`)
 				div#title= meta.name || host
 		div#content
diff --git a/packages/frontend/src/components/MkCustomEmojiDetailedDialog.vue b/packages/frontend/src/components/MkCustomEmojiDetailedDialog.vue
index c53bbca37c..d85231eb0b 100644
--- a/packages/frontend/src/components/MkCustomEmojiDetailedDialog.vue
+++ b/packages/frontend/src/components/MkCustomEmojiDetailedDialog.vue
@@ -46,7 +46,7 @@ SPDX-License-Identifier: AGPL-3.0-only
           <MkKeyValue :copy="emoji.url">
             <template #key>{{ i18n.ts.emojiUrl }}</template>
             <template #value>
-              <a :href="emoji.url" target="_blank">{{ emoji.url }}</a>
+              <a :href="emoji.url" rel="nofollow noopener" target="_blank">{{ emoji.url }}</a>
             </template>
           </MkKeyValue>
         </div>
diff --git a/packages/frontend/src/components/MkSignupDialog.rules.vue b/packages/frontend/src/components/MkSignupDialog.rules.vue
index 8cf7ce92ad..85c8d85e4e 100644
--- a/packages/frontend/src/components/MkSignupDialog.rules.vue
+++ b/packages/frontend/src/components/MkSignupDialog.rules.vue
@@ -34,8 +34,8 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<template #label>{{ tosPrivacyPolicyLabel }}</template>
 				<template #suffix><i v-if="agreeTosAndPrivacyPolicy" class="ti ti-check" style="color: var(--success)"></i></template>
 				<div class="_gaps_s">
-					<div v-if="availableTos"><a :href="instance.tosUrl" class="_link" target="_blank">{{ i18n.ts.termsOfService }} <i class="ti ti-external-link"></i></a></div>
-					<div v-if="availablePrivacyPolicy"><a :href="instance.privacyPolicyUrl" class="_link" target="_blank">{{ i18n.ts.privacyPolicy }} <i class="ti ti-external-link"></i></a></div>
+					<div v-if="availableTos"><a :href="instance.tosUrl" class="_link" rel="nofollow noopener" target="_blank">{{ i18n.ts.termsOfService }} <i class="ti ti-external-link"></i></a></div>
+					<div v-if="availablePrivacyPolicy"><a :href="instance.privacyPolicyUrl" class="_link" rel="nofollow noopener" target="_blank">{{ i18n.ts.privacyPolicy }} <i class="ti ti-external-link"></i></a></div>
 				</div>
 
 				<MkSwitch :modelValue="agreeTosAndPrivacyPolicy" style="margin-top: 16px;" @update:modelValue="updateAgreeTosAndPrivacyPolicy">{{ i18n.ts.agree }}</MkSwitch>
@@ -45,7 +45,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<template #label>{{ i18n.ts.basicNotesBeforeCreateAccount }}</template>
 				<template #suffix><i v-if="agreeNote" class="ti ti-check" style="color: var(--success)"></i></template>
 
-				<a href="https://misskey-hub.net/docs/for-users/onboarding/warning/" class="_link" target="_blank">{{ i18n.ts.basicNotesBeforeCreateAccount }} <i class="ti ti-external-link"></i></a>
+				<a href="https://misskey-hub.net/docs/for-users/onboarding/warning/" class="_link" rel="nofollow noopener" target="_blank">{{ i18n.ts.basicNotesBeforeCreateAccount }} <i class="ti ti-external-link"></i></a>
 
 				<MkSwitch :modelValue="agreeNote" style="margin-top: 16px;" data-cy-signup-rules-notes-agree @update:modelValue="updateAgreeNote">{{ i18n.ts.agree }}</MkSwitch>
 			</MkFolder>
diff --git a/packages/frontend/src/components/MkTutorialDialog.Timeline.vue b/packages/frontend/src/components/MkTutorialDialog.Timeline.vue
index 93181cf2b1..932681bd2d 100644
--- a/packages/frontend/src/components/MkTutorialDialog.Timeline.vue
+++ b/packages/frontend/src/components/MkTutorialDialog.Timeline.vue
@@ -19,7 +19,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 	<div :class="$style.divider"></div>
 	<I18n :src="i18n.ts._initialTutorial._timeline.description3" tag="div" style="padding: 0 16px;">
 		<template #link>
-			<a href="https://misskey-hub.net/docs/for-users/features/timeline/" target="_blank" class="_link">{{ i18n.ts.help }}</a>
+			<a href="https://misskey-hub.net/docs/for-users/features/timeline/" rel="nofollow noopener" target="_blank" class="_link">{{ i18n.ts.help }}</a>
 		</template>
 	</I18n>
 
diff --git a/packages/frontend/src/components/MkTutorialDialog.vue b/packages/frontend/src/components/MkTutorialDialog.vue
index 963e78a1ff..12d3d24643 100644
--- a/packages/frontend/src/components/MkTutorialDialog.vue
+++ b/packages/frontend/src/components/MkTutorialDialog.vue
@@ -130,7 +130,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 							<div style="font-size: 120%;">{{ i18n.ts._initialTutorial._done.title }}</div>
 							<I18n :src="i18n.ts._initialTutorial._done.description" tag="div" style="padding: 0 16px;">
 								<template #link>
-									<a href="https://misskey-hub.net/docs/for-users/" target="_blank" class="_link">{{ i18n.ts.help }}</a>
+									<a href="https://misskey-hub.net/docs/for-users/" rel="nofollow noopener" target="_blank" class="_link">{{ i18n.ts.help }}</a>
 								</template>
 							</I18n>
 							<div>{{ i18n.t('_initialAccountSetting.haveFun', { name: instance.name ?? host }) }}</div>
diff --git a/packages/frontend/src/components/form/link.vue b/packages/frontend/src/components/form/link.vue
index 4d711814b5..d4209b99d9 100644
--- a/packages/frontend/src/components/form/link.vue
+++ b/packages/frontend/src/components/form/link.vue
@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <template>
 <div :class="[$style.root, { [$style.inline]: inline }]">
-	<a v-if="external" :class="$style.main" class="_button" :href="to" target="_blank">
+	<a v-if="external" :class="$style.main" class="_button" :href="to" rel="nofollow noopener" target="_blank">
 		<span :class="$style.icon"><slot name="icon"></slot></span>
 		<span :class="$style.text"><slot></slot></span>
 		<span :class="$style.suffix">
diff --git a/packages/frontend/src/components/global/MkAd.vue b/packages/frontend/src/components/global/MkAd.vue
index 97feb40db5..f87397e34d 100644
--- a/packages/frontend/src/components/global/MkAd.vue
+++ b/packages/frontend/src/components/global/MkAd.vue
@@ -14,7 +14,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			[$style.form_vertical]: chosen.place === 'vertical',
 		}]"
 	>
-		<a :href="chosen.url" target="_blank" :class="$style.link">
+		<a :href="chosen.url" rel="noopener" target="_blank" :class="$style.link">
 			<img :src="chosen.imageUrl" :class="$style.img">
 			<button class="_button" :class="$style.i" @click.prevent.stop="toggleMenu"><i :class="$style.iIcon" class="ti ti-info-circle"></i></button>
 		</a>
diff --git a/packages/frontend/src/pages/about-misskey.vue b/packages/frontend/src/pages/about-misskey.vue
index f8eced8d72..2ed82e8f27 100644
--- a/packages/frontend/src/pages/about-misskey.vue
+++ b/packages/frontend/src/pages/about-misskey.vue
@@ -22,7 +22,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 					<button v-if="thereIsTreasure" class="_button treasure" @click="getTreasure"><img src="/fluent-emoji/1f3c6.png" class="treasureImg"></button>
 				</div>
 				<div style="text-align: center;">
-					{{ i18n.ts._aboutMisskey.about }}<br><a href="https://misskey-hub.net/docs/about-misskey/" target="_blank" class="_link">{{ i18n.ts.learnMore }}</a>
+					{{ i18n.ts._aboutMisskey.about }}<br><a href="https://misskey-hub.net/docs/about-misskey/" rel="nofollow noopener" target="_blank" class="_link">{{ i18n.ts.learnMore }}</a>
 				</div>
 				<div v-if="$i != null" style="text-align: center;">
 					<MkButton primary rounded inline @click="iLoveMisskey">I <Mfm text="$[jelly ❤]"/> #Misskey</MkButton>
diff --git a/packages/frontend/src/pages/admin-file.vue b/packages/frontend/src/pages/admin-file.vue
index 4a9c659a97..b05db7b3bc 100644
--- a/packages/frontend/src/pages/admin-file.vue
+++ b/packages/frontend/src/pages/admin-file.vue
@@ -8,7 +8,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 	<template #header><MkPageHeader v-model:tab="tab" :actions="headerActions" :tabs="headerTabs"/></template>
 	<MkSpacer v-if="file" :contentMax="600" :marginMin="16" :marginMax="32">
 		<div v-if="tab === 'overview'" class="cxqhhsmd _gaps_m">
-			<a class="thumbnail" :href="file.url" target="_blank">
+			<a class="thumbnail" :href="file.url" rel="nofollow noopener" target="_blank">
 				<MkDriveFileThumbnail class="thumbnail" :file="file" fit="contain"/>
 			</a>
 			<div>
diff --git a/packages/frontend/src/pages/settings/2fa.qrdialog.vue b/packages/frontend/src/pages/settings/2fa.qrdialog.vue
index 3d7bb06da2..38f56242cb 100644
--- a/packages/frontend/src/pages/settings/2fa.qrdialog.vue
+++ b/packages/frontend/src/pages/settings/2fa.qrdialog.vue
@@ -27,10 +27,10 @@ SPDX-License-Identifier: AGPL-3.0-only
 						<div class="_gaps">
 							<I18n :src="i18n.ts._2fa.step1" tag="div">
 								<template #a>
-									<a href="https://authy.com/" rel="noopener" target="_blank" class="_link">Authy</a>
+									<a href="https://authy.com/" rel="nofollow noopener" target="_blank" class="_link">Authy</a>
 								</template>
 								<template #b>
-									<a href="https://support.google.com/accounts/answer/1066447" rel="noopener" target="_blank" class="_link">Google Authenticator</a>
+									<a href="https://support.google.com/accounts/answer/1066447" rel="nofollow noopener" target="_blank" class="_link">Google Authenticator</a>
 								</template>
 							</I18n>
 							<div>{{ i18n.ts._2fa.step2 }}<br>{{ i18n.ts._2fa.step2Click }}</div>
diff --git a/packages/frontend/src/ui/visitor.vue b/packages/frontend/src/ui/visitor.vue
index f1d40b24a4..2c86d329aa 100644
--- a/packages/frontend/src/ui/visitor.vue
+++ b/packages/frontend/src/ui/visitor.vue
@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <template>
 <div class="mk-app">
-	<a v-if="root" href="https://github.com/misskey-dev/misskey" target="_blank" class="github-corner" aria-label="View source on GitHub"><svg width="80" height="80" viewBox="0 0 250 250" style="fill:var(--panel); color:var(--fg); position: fixed; z-index: 10; top: 0; border: 0; right: 0;" aria-hidden="true"><path d="M0,0 L115,115 L130,115 L142,142 L250,250 L250,0 Z"></path><path d="M128.3,109.0 C113.8,99.7 119.0,89.6 119.0,89.6 C122.0,82.7 120.5,78.6 120.5,78.6 C119.2,72.0 123.4,76.3 123.4,76.3 C127.3,80.9 125.5,87.3 125.5,87.3 C122.9,97.6 130.6,101.9 134.4,103.2" fill="currentColor" style="transform-origin: 130px 106px;" class="octo-arm"></path><path d="M115.0,115.0 C114.9,115.1 118.7,116.5 119.8,115.4 L133.7,101.6 C136.9,99.2 139.9,98.4 142.2,98.6 C133.8,88.0 127.5,74.4 143.8,58.0 C148.5,53.4 154.0,51.2 159.7,51.0 C160.3,49.4 163.2,43.6 171.4,40.1 C171.4,40.1 176.1,42.5 178.8,56.2 C183.1,58.6 187.2,61.8 190.9,65.4 C194.5,69.0 197.7,73.2 200.1,77.6 C213.8,80.2 216.3,84.9 216.3,84.9 C212.7,93.1 206.9,96.0 205.4,96.6 C205.1,102.4 203.0,107.8 198.3,112.5 C181.9,128.9 168.3,122.5 157.7,114.1 C157.9,116.9 156.7,120.9 152.7,124.9 L141.0,136.5 C139.8,137.7 141.6,141.9 141.8,141.8 Z" fill="currentColor" class="octo-body"></path></svg></a>
+	<a v-if="root" href="https://github.com/misskey-dev/misskey" rel="nofollow noopener" target="_blank" class="github-corner" aria-label="View source on GitHub"><svg width="80" height="80" viewBox="0 0 250 250" style="fill:var(--panel); color:var(--fg); position: fixed; z-index: 10; top: 0; border: 0; right: 0;" aria-hidden="true"><path d="M0,0 L115,115 L130,115 L142,142 L250,250 L250,0 Z"></path><path d="M128.3,109.0 C113.8,99.7 119.0,89.6 119.0,89.6 C122.0,82.7 120.5,78.6 120.5,78.6 C119.2,72.0 123.4,76.3 123.4,76.3 C127.3,80.9 125.5,87.3 125.5,87.3 C122.9,97.6 130.6,101.9 134.4,103.2" fill="currentColor" style="transform-origin: 130px 106px;" class="octo-arm"></path><path d="M115.0,115.0 C114.9,115.1 118.7,116.5 119.8,115.4 L133.7,101.6 C136.9,99.2 139.9,98.4 142.2,98.6 C133.8,88.0 127.5,74.4 143.8,58.0 C148.5,53.4 154.0,51.2 159.7,51.0 C160.3,49.4 163.2,43.6 171.4,40.1 C171.4,40.1 176.1,42.5 178.8,56.2 C183.1,58.6 187.2,61.8 190.9,65.4 C194.5,69.0 197.7,73.2 200.1,77.6 C213.8,80.2 216.3,84.9 216.3,84.9 C212.7,93.1 206.9,96.0 205.4,96.6 C205.1,102.4 203.0,107.8 198.3,112.5 C181.9,128.9 168.3,122.5 157.7,114.1 C157.9,116.9 156.7,120.9 152.7,124.9 L141.0,136.5 C139.8,137.7 141.6,141.9 141.8,141.8 Z" fill="currentColor" class="octo-body"></path></svg></a>
 
 	<div v-if="!narrow && !root" class="side">
 		<div class="banner" :style="{ backgroundImage: instance.backgroundImageUrl ? `url(${ instance.backgroundImageUrl })` : 'none' }"></div>