diff --git a/packages/backend/migration/1753574755478-change-chat_message-text-type.js b/packages/backend/migration/1753574755478-change-chat_message-text-type.js
new file mode 100644
index 0000000000..d286f8ff3a
--- /dev/null
+++ b/packages/backend/migration/1753574755478-change-chat_message-text-type.js
@@ -0,0 +1,16 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export class ChangeChatMessageTextType1753574755478 {
+	name = 'ChangeChatMessageTextType1753574755478'
+
+	async up(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "chat_message" ALTER COLUMN "text" TYPE text`);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "chat_message" ALTER COLUMN "text" TYPE varchar(4096)`);
+	}
+}
diff --git a/packages/backend/src/models/ChatMessage.ts b/packages/backend/src/models/ChatMessage.ts
index 3d2b64268e..536947335b 100644
--- a/packages/backend/src/models/ChatMessage.ts
+++ b/packages/backend/src/models/ChatMessage.ts
@@ -50,8 +50,8 @@ export class MiChatMessage {
 	@JoinColumn()
 	public toRoom: MiChatRoom | null;
 
-	@Column('varchar', {
-		length: 4096, nullable: true,
+	@Column('text', {
+		nullable: true,
 	})
 	public text: string | null;
 
diff --git a/packages/frontend/src/pages/chat/room.form.vue b/packages/frontend/src/pages/chat/room.form.vue
index 9389b16ce7..8b1fed5156 100644
--- a/packages/frontend/src/pages/chat/room.form.vue
+++ b/packages/frontend/src/pages/chat/room.form.vue
@@ -43,7 +43,7 @@ import * as os from '@/os.js';
 import { i18n } from '@/i18n.js';
 import { uploadFile } from '@/utility/upload.js';
 import { miLocalStorage } from '@/local-storage.js';
-import { misskeyApi } from '@/utility/misskey-api.js';
+import { misskeyApi, printError } from '@/utility/misskey-api.js';
 import { prefer } from '@/preferences.js';
 import { Autocomplete } from '@/utility/autocomplete.js';
 import { emojiPicker } from '@/utility/emoji-picker.js';
@@ -194,8 +194,13 @@ function send() {
 		}).then(message => {
 			clear();
 		}).catch(err => {
-			console.error(err);
-		}).then(() => {
+			console.error('Error in chat:', err);
+			return os.alert({
+				type: 'error',
+				title: i18n.ts.error,
+				text: printError(err),
+			});
+		}).finally(() => {
 			sending.value = false;
 		});
 	} else if (props.room) {
@@ -206,8 +211,13 @@ function send() {
 		}).then(message => {
 			clear();
 		}).catch(err => {
-			console.error(err);
-		}).then(() => {
+			console.error('Error in chat:', err);
+			return os.alert({
+				type: 'error',
+				title: i18n.ts.error,
+				text: printError(err),
+			});
+		}).finally(() => {
 			sending.value = false;
 		});
 	}
diff --git a/packages/frontend/src/utility/misskey-api.ts b/packages/frontend/src/utility/misskey-api.ts
index f8c4657655..a5736e11ed 100644
--- a/packages/frontend/src/utility/misskey-api.ts
+++ b/packages/frontend/src/utility/misskey-api.ts
@@ -144,3 +144,21 @@ export function misskeyApiGet<
 
 	return promise;
 }
+
+export function printError(error: unknown): string {
+	if (error != null && typeof(error) === 'object') {
+		if ('info' in error && typeof (error.info) === 'object' && error.info) {
+			if ('e' in error.info && typeof (error.info.e) === 'object' && error.info.e) {
+				if ('message' in error.info.e && typeof (error.info.e.message) === 'string') return error.info.e.message;
+				if ('code' in error.info.e && typeof (error.info.e.code) === 'string') return error.info.e.code;
+				if ('id' in error.info.e && typeof (error.info.e.id) === 'string') return error.info.e.id;
+			}
+		}
+
+		if ('message' in error && typeof (error.message) === 'string') return error.message;
+		if ('code' in error && typeof (error.code) === 'string') return error.code;
+		if ('id' in error && typeof (error.id) === 'string') return error.id;
+	}
+
+	return String(error);
+}