diff --git a/src/components/video-editor/SettingsPanel.tsx b/src/components/video-editor/SettingsPanel.tsx
index 82e106c5..5ac59796 100644
--- a/src/components/video-editor/SettingsPanel.tsx
+++ b/src/components/video-editor/SettingsPanel.tsx
@@ -43,6 +43,7 @@ import { getTestId } from "@/utils/getTestId";
 import ColorPicker from "../ui/color-picker";
 import { AnnotationSettingsPanel } from "./AnnotationSettingsPanel";
 import { BlurSettingsPanel } from "./BlurSettingsPanel";
+import { BACKGROUND_IMAGE_ACCEPT, isSupportedBackgroundImageType } from "./backgroundImageUpload";
 import { CropControl } from "./CropControl";
 import { KeyboardShortcutsHelp } from "./KeyboardShortcutsHelp";
 import type {
@@ -459,9 +460,7 @@ export function SettingsPanel({
 
 		const file = files[0];
 
-		// Validate file type - only allow JPG/JPEG
-		const validTypes = ["image/jpeg", "image/jpg"];
-		if (!validTypes.includes(file.type)) {
+		if (!isSupportedBackgroundImageType(file.type, file.name)) {
 			toast.error(t("imageUpload.invalidFileType"), {
 				description: t("imageUpload.jpgOnly"),
 			});
@@ -1041,7 +1040,7 @@ export function SettingsPanel({
 											type="file"
 											ref={fileInputRef}
 											onChange={handleImageUpload}
-											accept=".jpg,.jpeg,image/jpeg"
+											accept={BACKGROUND_IMAGE_ACCEPT}
 											className="hidden"
 										/>
 										<Button
diff --git a/src/components/video-editor/backgroundImageUpload.test.ts b/src/components/video-editor/backgroundImageUpload.test.ts
new file mode 100644
index 00000000..d83ca3a0
--- /dev/null
+++ b/src/components/video-editor/backgroundImageUpload.test.ts
@@ -0,0 +1,20 @@
+import { describe, expect, it } from "vitest";
+import { isSupportedBackgroundImageType } from "./backgroundImageUpload";
+
+describe("background image upload validation", () => {
+	it("accepts PNG images for custom backgrounds", () => {
+		expect(isSupportedBackgroundImageType("image/png", "生成画像1.png")).toBe(true);
+	});
+
+	it("accepts PNG images by extension when the browser does not provide a MIME type", () => {
+		expect(isSupportedBackgroundImageType("", "生成画像1.png")).toBe(true);
+	});
+
+	it("keeps rejecting non-image uploads", () => {
+		expect(isSupportedBackgroundImageType("text/plain", "notes.txt")).toBe(false);
+	});
+
+	it("does not allow extension fallback for explicit unsupported MIME types", () => {
+		expect(isSupportedBackgroundImageType("text/plain", "notes.png")).toBe(false);
+	});
+});
diff --git a/src/components/video-editor/backgroundImageUpload.ts b/src/components/video-editor/backgroundImageUpload.ts
new file mode 100644
index 00000000..ebc256a2
--- /dev/null
+++ b/src/components/video-editor/backgroundImageUpload.ts
@@ -0,0 +1,20 @@
+const SUPPORTED_BACKGROUND_IMAGE_TYPES = new Set(["image/jpeg", "image/jpg", "image/png"]);
+const SUPPORTED_BACKGROUND_IMAGE_EXTENSIONS = new Set([".jpg", ".jpeg", ".png"]);
+
+export const BACKGROUND_IMAGE_ACCEPT = ".jpg,.jpeg,.png,image/jpeg,image/png";
+
+export function isSupportedBackgroundImageType(type: string, fileName: string): boolean {
+	const normalizedType = type.trim().toLowerCase();
+	if (SUPPORTED_BACKGROUND_IMAGE_TYPES.has(normalizedType)) {
+		return true;
+	}
+
+	if (normalizedType) {
+		return false;
+	}
+
+	const lowerName = fileName.trim().toLowerCase();
+	return [...SUPPORTED_BACKGROUND_IMAGE_EXTENSIONS].some((extension) =>
+		lowerName.endsWith(extension),
+	);
+}
diff --git a/src/i18n/locales/en/settings.json b/src/i18n/locales/en/settings.json
index 9b85c2bf..ff214722 100644
--- a/src/i18n/locales/en/settings.json
+++ b/src/i18n/locales/en/settings.json
@@ -93,7 +93,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "Invalid file type",
-		"jpgOnly": "Please upload a JPG or JPEG image file.",
+		"jpgOnly": "Please upload a JPG, JPEG, or PNG image file.",
 		"uploadSuccess": "Custom image uploaded successfully!",
 		"failedToUpload": "Failed to upload image",
 		"errorReading": "There was an error reading the file."
diff --git a/src/i18n/locales/es/settings.json b/src/i18n/locales/es/settings.json
index 423b158e..8dee9c2b 100644
--- a/src/i18n/locales/es/settings.json
+++ b/src/i18n/locales/es/settings.json
@@ -93,7 +93,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "Tipo de archivo no válido",
-		"jpgOnly": "Por favor sube un archivo de imagen JPG o JPEG.",
+		"jpgOnly": "Por favor sube un archivo de imagen JPG, JPEG o PNG.",
 		"uploadSuccess": "¡Imagen personalizada subida exitosamente!",
 		"failedToUpload": "Error al subir la imagen",
 		"errorReading": "Hubo un error al leer el archivo."
diff --git a/src/i18n/locales/fr/settings.json b/src/i18n/locales/fr/settings.json
index 66df1ba9..56f2642a 100644
--- a/src/i18n/locales/fr/settings.json
+++ b/src/i18n/locales/fr/settings.json
@@ -100,7 +100,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "Type de fichier invalide",
-		"jpgOnly": "Veuillez téléverser un fichier image JPG ou JPEG.",
+		"jpgOnly": "Veuillez téléverser un fichier image JPG, JPEG ou PNG.",
 		"uploadSuccess": "Image personnalisée téléversée avec succès !",
 		"failedToUpload": "Échec du téléversement de l'image",
 		"errorReading": "Une erreur s'est produite lors de la lecture du fichier."
diff --git a/src/i18n/locales/ja-JP/settings.json b/src/i18n/locales/ja-JP/settings.json
index 129217c5..cde1f1db 100644
--- a/src/i18n/locales/ja-JP/settings.json
+++ b/src/i18n/locales/ja-JP/settings.json
@@ -100,7 +100,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "無効なファイル形式",
-		"jpgOnly": "JPG または JPEG 画像ファイルをアップロードしてください。",
+		"jpgOnly": "JPG、JPEG、または PNG 画像ファイルをアップロードしてください。",
 		"uploadSuccess": "カスタム画像が正常にアップロードされました！",
 		"failedToUpload": "画像のアップロードに失敗しました",
 		"errorReading": "ファイルの読み取り中にエラーが発生しました。"
diff --git a/src/i18n/locales/ko-KR/settings.json b/src/i18n/locales/ko-KR/settings.json
index 08fdb3c5..c7df60d6 100644
--- a/src/i18n/locales/ko-KR/settings.json
+++ b/src/i18n/locales/ko-KR/settings.json
@@ -93,7 +93,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "지원하지 않는 파일 형식입니다",
-		"jpgOnly": "JPG 또는 JPEG 이미지 파일을 업로드해 주세요.",
+		"jpgOnly": "JPG, JPEG 또는 PNG 이미지 파일을 업로드해 주세요.",
 		"uploadSuccess": "커스텀 이미지가 성공적으로 업로드되었습니다!",
 		"failedToUpload": "이미지 업로드에 실패했습니다",
 		"errorReading": "파일을 읽는 중 오류가 발생했습니다."
diff --git a/src/i18n/locales/tr/settings.json b/src/i18n/locales/tr/settings.json
index 143c467c..03915829 100644
--- a/src/i18n/locales/tr/settings.json
+++ b/src/i18n/locales/tr/settings.json
@@ -93,7 +93,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "Geçersiz dosya türü",
-		"jpgOnly": "Lütfen bir JPG veya JPEG görüntü dosyası yükleyin.",
+		"jpgOnly": "Lütfen JPG, JPEG veya PNG görüntü dosyası yükleyin.",
 		"uploadSuccess": "Özel görüntü başarıyla yüklendi!",
 		"failedToUpload": "Görüntü yüklenemedi",
 		"errorReading": "Dosya okunurken bir hata oluştu."
diff --git a/src/i18n/locales/zh-CN/settings.json b/src/i18n/locales/zh-CN/settings.json
index 708ae5ea..d2a10c15 100644
--- a/src/i18n/locales/zh-CN/settings.json
+++ b/src/i18n/locales/zh-CN/settings.json
@@ -93,7 +93,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "无效的文件类型",
-		"jpgOnly": "请上传 JPG 或 JPEG 格式的图片文件。",
+		"jpgOnly": "请上传 JPG、JPEG 或 PNG 格式的图片文件。",
 		"uploadSuccess": "自定义图片上传成功！",
 		"failedToUpload": "上传图片失败",
 		"errorReading": "读取文件时出错。"
diff --git a/src/i18n/locales/zh-TW/settings.json b/src/i18n/locales/zh-TW/settings.json
index c93e8d5d..6f2fb08c 100644
--- a/src/i18n/locales/zh-TW/settings.json
+++ b/src/i18n/locales/zh-TW/settings.json
@@ -100,7 +100,7 @@
 	},
 	"imageUpload": {
 		"invalidFileType": "無效的檔案類型",
-		"jpgOnly": "請上傳 JPG 或 JPEG 格式的圖片檔案。",
+		"jpgOnly": "請上傳 JPG、JPEG 或 PNG 格式的圖片檔案。",
 		"uploadSuccess": "自訂圖片上傳成功！",
 		"failedToUpload": "上傳圖片失敗",
 		"errorReading": "讀取檔案時出錯。"