diff --git a/locales/en-US.yml b/locales/en-US.yml
index 275229b791..ffe9b4a0f2 100644
--- a/locales/en-US.yml
+++ b/locales/en-US.yml
@@ -1817,6 +1817,7 @@ pages:
   read-page: "Viewing the source"
   page-created: "Created the page!"
   page-updated: "Updated the page"
+  name-already-exists: "Specified page url already exists"
   are-you-sure-delete: "Do you want to delete this page?"
   page-deleted: "The page has been deleted"
   edit-this-page: "Edit this page"
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 5a1d8d707d..ebc41b0671 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -2015,6 +2015,7 @@ pages:
   read-page: "ソースを表示中"
   page-created: "ページを作成しました"
   page-updated: "ページを更新しました"
+  name-already-exists: "指定されたページURLは既に存在しています"
   are-you-sure-delete: "このページを削除しますか？"
   page-deleted: "ページを削除しました"
   edit-this-page: "このページを編集"
diff --git a/src/client/app/common/views/pages/page-editor/page-editor.vue b/src/client/app/common/views/pages/page-editor/page-editor.vue
index b29bbd4d35..b8db59da41 100644
--- a/src/client/app/common/views/pages/page-editor/page-editor.vue
+++ b/src/client/app/common/views/pages/page-editor/page-editor.vue
@@ -220,37 +220,38 @@ export default Vue.extend({
 
 	methods: {
 		save() {
+			const options = {
+				title: this.title.trim(),
+				name: this.name.trim(),
+				summary: this.summary,
+				font: this.font,
+				hideTitleWhenPinned: this.hideTitleWhenPinned,
+				alignCenter: this.alignCenter,
+				content: this.content,
+				variables: this.variables,
+				eyeCatchingImageId: this.eyeCatchingImageId,
+			};
+
 			if (this.pageId) {
-				this.$root.api('pages/update', {
-					pageId: this.pageId,
-					title: this.title.trim(),
-					name: this.name.trim(),
-					summary: this.summary,
-					font: this.font,
-					hideTitleWhenPinned: this.hideTitleWhenPinned,
-					alignCenter: this.alignCenter,
-					content: this.content,
-					variables: this.variables,
-					eyeCatchingImageId: this.eyeCatchingImageId,
-				}).then(page => {
+				options.pageId = this.pageId;
+				this.$root.api('pages/update', options)
+				.then(page => {
 					this.currentName = this.name.trim();
 					this.$root.dialog({
 						type: 'success',
 						text: this.$t('page-updated')
 					});
+				}).catch(err => {
+					if(err.id == '2298a392-d4a1-44c5-9ebb-ac1aeaa5a9ab'){
+						this.$root.dialog({
+							type: 'error',
+							text: this.$t('name-already-exists')
+						});
+					}
 				});
 			} else {
-				this.$root.api('pages/create', {
-					title: this.title.trim(),
-					name: this.name.trim(),
-					summary: this.summary,
-					font: this.font,
-					hideTitleWhenPinned: this.hideTitleWhenPinned,
-					alignCenter: this.alignCenter,
-					content: this.content,
-					variables: this.variables,
-					eyeCatchingImageId: this.eyeCatchingImageId,
-				}).then(page => {
+				this.$root.api('pages/create', options)
+				.then(page => {
 					this.pageId = page.id;
 					this.currentName = this.name.trim();
 					this.$root.dialog({
@@ -258,6 +259,13 @@ export default Vue.extend({
 						text: this.$t('page-created')
 					});
 					this.$router.push(`/i/pages/edit/${this.pageId}`);
+				}).catch(err => {
+					if(err.id == '4650348e-301c-499a-83c9-6aa988c66bc1'){
+						this.$root.dialog({
+							type: 'error',
+							text: this.$t('name-already-exists')
+						});
+					}
 				});
 			}
 		},
diff --git a/src/server/api/endpoints/pages/create.ts b/src/server/api/endpoints/pages/create.ts
index a49a5d37b8..f18c82ffde 100644
--- a/src/server/api/endpoints/pages/create.ts
+++ b/src/server/api/endpoints/pages/create.ts
@@ -76,6 +76,11 @@ export const meta = {
 			code: 'NO_SUCH_FILE',
 			id: 'b7b97489-0f66-4b12-a5ff-b21bd63f6e1c'
 		},
+		nameAlreadyExists: {
+			message: 'Specified name already exists.',
+			code: 'NAME_ALREADY_EXISTS',
+			id: '4650348e-301c-499a-83c9-6aa988c66bc1'
+		}
 	}
 };
 
@@ -92,6 +97,15 @@ export default define(meta, async (ps, user) => {
 		}
 	}
 
+	await Pages.find({
+		userId: user.id,
+		name: ps.name
+	}).then(result => {
+		if (result.length > 0) {
+			throw new ApiError(meta.errors.nameAlreadyExists);
+		}
+	});
+
 	const page = await Pages.save(new Page({
 		id: genId(),
 		createdAt: new Date(),
diff --git a/src/server/api/endpoints/pages/update.ts b/src/server/api/endpoints/pages/update.ts
index 9daf5e9cae..564beb84cb 100644
--- a/src/server/api/endpoints/pages/update.ts
+++ b/src/server/api/endpoints/pages/update.ts
@@ -4,6 +4,7 @@ import define from '../../define';
 import { ApiError } from '../../error';
 import { Pages, DriveFiles } from '../../../../models';
 import { ID } from '../../../../misc/cafy-id';
+import { Not } from 'typeorm';
 
 export const meta = {
 	desc: {
@@ -85,6 +86,11 @@ export const meta = {
 			code: 'NO_SUCH_FILE',
 			id: 'cfc23c7c-3887-490e-af30-0ed576703c82'
 		},
+		nameAlreadyExists: {
+			message: 'Specified name already exists.',
+			code: 'NAME_ALREADY_EXISTS',
+			id: '2298a392-d4a1-44c5-9ebb-ac1aeaa5a9ab'
+		}
 	}
 };
 
@@ -109,6 +115,16 @@ export default define(meta, async (ps, user) => {
 		}
 	}
 
+	await Pages.find({
+		id: Not(ps.pageId),
+		userId: user.id,
+		name: ps.name
+	}).then(result => {
+		if (result.length > 0) {
+			throw new ApiError(meta.errors.nameAlreadyExists);
+		}
+	});
+
 	await Pages.update(page.id, {
 		updatedAt: new Date(),
 		title: ps.title,