diff --git a/apps/readest-app/AGENTS.md b/apps/readest-app/AGENTS.md
index 7ec1ed68..72df3adc 100644
--- a/apps/readest-app/AGENTS.md
+++ b/apps/readest-app/AGENTS.md
@@ -75,6 +75,10 @@ Platform-specific code lives in `src-tauri/src/{macos,windows,android,ios}/`. Cu
 - No lookbehind regex in build output — verified by `check:lookbehind-regex`.
 - Run `pnpm build-check` (builds both targets + runs all checks) before submitting.
 
+### i18n
+
+See [docs/i18n.md](docs/i18n.md) for the key-as-content translation approach, `stubTranslation` usage in non-React modules, and extraction workflow.
+
 ### Safe Area Insets
 
 See [docs/safe-area-insets.md](docs/safe-area-insets.md) for rules on handling top/bottom insets for UI elements near screen edges.
diff --git a/apps/readest-app/docs/i18n.md b/apps/readest-app/docs/i18n.md
new file mode 100644
index 00000000..6e88d918
--- /dev/null
+++ b/apps/readest-app/docs/i18n.md
@@ -0,0 +1,48 @@
+## i18n Guide
+
+Readest uses a **key-as-content** approach — English strings are the translation keys. The English locale (`en/translation.json`) is empty because keys serve as content. Other locales contain actual translations.
+
+### In React Components
+
+```tsx
+import { useTranslation } from '@/hooks/useTranslation';
+
+const _ = useTranslation();
+_('Progress synced');
+```
+
+### In Non-React Modules
+
+Two-step process:
+
+**1. Declaration** — Use `stubTranslation` to mark strings for scanner extraction (returns key as-is, does NOT translate):
+
+```ts
+import { stubTranslation as _ } from '@/utils/misc';
+
+// These calls only register keys for extraction
+_('Reveal in Finder');
+_('Reveal in Explorer');
+```
+
+**2. Usage** — In the React component that consumes the value, apply the real `_()` from `useTranslation`:
+
+```tsx
+const _ = useTranslation();
+const label = _(getRevealLabel()); // translates at runtime
+```
+
+### Extraction & Translation
+
+```bash
+pnpm i18n:extract    # Scans codebase, adds new keys with __STRING_NOT_TRANSLATED__
+```
+
+- Translation files: `public/locales/<locale>/translation.json`
+- Only `_('KEY')` and `_('KEY', options)` patterns are recognized by i18next-scanner
+
+### Rules
+
+- `stubTranslation` is for extraction only — always apply `_()` from `useTranslation` in the component for runtime translation.
+- Fallback: when no translation exists, the English key itself is displayed.
+- Error messages: register keys with `stubTranslation` in utility modules (e.g. `src/services/errors.ts`), return the English key from helpers, wrap with `_()` in the component.
diff --git a/apps/readest-app/public/locales/ar/translation.json b/apps/readest-app/public/locales/ar/translation.json
index a771caa1..46a3ac3c 100644
--- a/apps/readest-app/public/locales/ar/translation.json
+++ b/apps/readest-app/public/locales/ar/translation.json
@@ -1117,5 +1117,6 @@
   "Decrease font size": "تصغير حجم الخط",
   "Increase font size": "تكبير حجم الخط",
   "Focus": "تركيز",
-  "Theme color": "لون السمة"
+  "Theme color": "لون السمة",
+  "Import failed": "فشل الاستيراد"
 }
diff --git a/apps/readest-app/public/locales/bn/translation.json b/apps/readest-app/public/locales/bn/translation.json
index e77286db..cf03b4a6 100644
--- a/apps/readest-app/public/locales/bn/translation.json
+++ b/apps/readest-app/public/locales/bn/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "ফন্টের আকার কমান",
   "Increase font size": "ফন্টের আকার বাড়ান",
   "Focus": "ফোকাস",
-  "Theme color": "থিম রঙ"
+  "Theme color": "থিম রঙ",
+  "Import failed": "আমদানি ব্যর্থ"
 }
diff --git a/apps/readest-app/public/locales/bo/translation.json b/apps/readest-app/public/locales/bo/translation.json
index b2141e24..caf2d887 100644
--- a/apps/readest-app/public/locales/bo/translation.json
+++ b/apps/readest-app/public/locales/bo/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "ཡིག་གཟུགས་ཆུང་དུ་གཏོང་བ",
   "Increase font size": "ཡིག་གཟུགས་ཆེ་རུ་གཏོང་བ",
   "Focus": "དམིགས་གཏད",
-  "Theme color": "བརྗོད་དོན་ཚོན་མདོག"
+  "Theme color": "བརྗོད་དོན་ཚོན་མདོག",
+  "Import failed": "ནང་འདྲེན་མི་ཐུབ།"
 }
diff --git a/apps/readest-app/public/locales/de/translation.json b/apps/readest-app/public/locales/de/translation.json
index ecef94af..3dda93be 100644
--- a/apps/readest-app/public/locales/de/translation.json
+++ b/apps/readest-app/public/locales/de/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "Schriftgröße verkleinern",
   "Increase font size": "Schriftgröße vergrößern",
   "Focus": "Fokus",
-  "Theme color": "Themenfarbe"
+  "Theme color": "Themenfarbe",
+  "Import failed": "Import fehlgeschlagen"
 }
diff --git a/apps/readest-app/public/locales/el/translation.json b/apps/readest-app/public/locales/el/translation.json
index 26d5d33e..8da4d004 100644
--- a/apps/readest-app/public/locales/el/translation.json
+++ b/apps/readest-app/public/locales/el/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "Μείωση μεγέθους γραμματοσειράς",
   "Increase font size": "Αύξηση μεγέθους γραμματοσειράς",
   "Focus": "Εστίαση",
-  "Theme color": "Χρώμα θέματος"
+  "Theme color": "Χρώμα θέματος",
+  "Import failed": "Η εισαγωγή απέτυχε"
 }
diff --git a/apps/readest-app/public/locales/es/translation.json b/apps/readest-app/public/locales/es/translation.json
index b7f5d2cf..cdb1032c 100644
--- a/apps/readest-app/public/locales/es/translation.json
+++ b/apps/readest-app/public/locales/es/translation.json
@@ -1081,5 +1081,6 @@
   "Decrease font size": "Reducir tamaño de fuente",
   "Increase font size": "Aumentar tamaño de fuente",
   "Focus": "Enfoque",
-  "Theme color": "Color del tema"
+  "Theme color": "Color del tema",
+  "Import failed": "Error de importación"
 }
diff --git a/apps/readest-app/public/locales/fa/translation.json b/apps/readest-app/public/locales/fa/translation.json
index 7865e154..ad781140 100644
--- a/apps/readest-app/public/locales/fa/translation.json
+++ b/apps/readest-app/public/locales/fa/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "کاهش اندازه قلم",
   "Increase font size": "افزایش اندازه قلم",
   "Focus": "تمرکز",
-  "Theme color": "رنگ پوسته"
+  "Theme color": "رنگ پوسته",
+  "Import failed": "وارد کردن ناموفق بود"
 }
diff --git a/apps/readest-app/public/locales/fr/translation.json b/apps/readest-app/public/locales/fr/translation.json
index 8dd2848f..b2b44fe7 100644
--- a/apps/readest-app/public/locales/fr/translation.json
+++ b/apps/readest-app/public/locales/fr/translation.json
@@ -1081,5 +1081,6 @@
   "Decrease font size": "Réduire la taille de police",
   "Increase font size": "Augmenter la taille de police",
   "Focus": "Focus",
-  "Theme color": "Couleur du thème"
+  "Theme color": "Couleur du thème",
+  "Import failed": "Échec de l'importation"
 }
diff --git a/apps/readest-app/public/locales/he/translation.json b/apps/readest-app/public/locales/he/translation.json
index e65ce632..b31e2b08 100644
--- a/apps/readest-app/public/locales/he/translation.json
+++ b/apps/readest-app/public/locales/he/translation.json
@@ -1081,5 +1081,6 @@
   "Decrease font size": "הקטן גודל גופן",
   "Increase font size": "הגדל גודל גופן",
   "Focus": "מיקוד",
-  "Theme color": "צבע ערכת נושא"
+  "Theme color": "צבע ערכת נושא",
+  "Import failed": "הייבוא נכשל"
 }
diff --git a/apps/readest-app/public/locales/hi/translation.json b/apps/readest-app/public/locales/hi/translation.json
index d762da57..e5c4cc21 100644
--- a/apps/readest-app/public/locales/hi/translation.json
+++ b/apps/readest-app/public/locales/hi/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "फ़ॉन्ट आकार घटाएँ",
   "Increase font size": "फ़ॉन्ट आकार बढ़ाएँ",
   "Focus": "फ़ोकस",
-  "Theme color": "थीम रंग"
+  "Theme color": "थीम रंग",
+  "Import failed": "आयात विफल"
 }
diff --git a/apps/readest-app/public/locales/id/translation.json b/apps/readest-app/public/locales/id/translation.json
index 10e03f3c..88c6b66f 100644
--- a/apps/readest-app/public/locales/id/translation.json
+++ b/apps/readest-app/public/locales/id/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "Perkecil ukuran font",
   "Increase font size": "Perbesar ukuran font",
   "Focus": "Fokus",
-  "Theme color": "Warna tema"
+  "Theme color": "Warna tema",
+  "Import failed": "Impor gagal"
 }
diff --git a/apps/readest-app/public/locales/it/translation.json b/apps/readest-app/public/locales/it/translation.json
index afd87a22..8fe83772 100644
--- a/apps/readest-app/public/locales/it/translation.json
+++ b/apps/readest-app/public/locales/it/translation.json
@@ -1081,5 +1081,6 @@
   "Decrease font size": "Riduci dimensione carattere",
   "Increase font size": "Aumenta dimensione carattere",
   "Focus": "Messa a fuoco",
-  "Theme color": "Colore del tema"
+  "Theme color": "Colore del tema",
+  "Import failed": "Importazione fallita"
 }
diff --git a/apps/readest-app/public/locales/ja/translation.json b/apps/readest-app/public/locales/ja/translation.json
index 3b33bea0..2ad460c5 100644
--- a/apps/readest-app/public/locales/ja/translation.json
+++ b/apps/readest-app/public/locales/ja/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "文字サイズを縮小",
   "Increase font size": "文字サイズを拡大",
   "Focus": "フォーカス",
-  "Theme color": "テーマカラー"
+  "Theme color": "テーマカラー",
+  "Import failed": "インポートに失敗しました"
 }
diff --git a/apps/readest-app/public/locales/ko/translation.json b/apps/readest-app/public/locales/ko/translation.json
index ff41d935..d4823f8b 100644
--- a/apps/readest-app/public/locales/ko/translation.json
+++ b/apps/readest-app/public/locales/ko/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "글꼴 크기 줄이기",
   "Increase font size": "글꼴 크기 늘리기",
   "Focus": "초점",
-  "Theme color": "테마 색상"
+  "Theme color": "테마 색상",
+  "Import failed": "가져오기 실패"
 }
diff --git a/apps/readest-app/public/locales/ms/translation.json b/apps/readest-app/public/locales/ms/translation.json
index d124a6e4..e454cd56 100644
--- a/apps/readest-app/public/locales/ms/translation.json
+++ b/apps/readest-app/public/locales/ms/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "Kecilkan saiz fon",
   "Increase font size": "Besarkan saiz fon",
   "Focus": "Fokus",
-  "Theme color": "Warna tema"
+  "Theme color": "Warna tema",
+  "Import failed": "Import gagal"
 }
diff --git a/apps/readest-app/public/locales/nl/translation.json b/apps/readest-app/public/locales/nl/translation.json
index 1bee1aa7..f88699d7 100644
--- a/apps/readest-app/public/locales/nl/translation.json
+++ b/apps/readest-app/public/locales/nl/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "Lettergrootte verkleinen",
   "Increase font size": "Lettergrootte vergroten",
   "Focus": "Focus",
-  "Theme color": "Themakleur"
+  "Theme color": "Themakleur",
+  "Import failed": "Import mislukt"
 }
diff --git a/apps/readest-app/public/locales/pl/translation.json b/apps/readest-app/public/locales/pl/translation.json
index 27c89c71..1fb4a212 100644
--- a/apps/readest-app/public/locales/pl/translation.json
+++ b/apps/readest-app/public/locales/pl/translation.json
@@ -1093,5 +1093,6 @@
   "Decrease font size": "Zmniejsz rozmiar czcionki",
   "Increase font size": "Zwiększ rozmiar czcionki",
   "Focus": "Fokus",
-  "Theme color": "Kolor motywu"
+  "Theme color": "Kolor motywu",
+  "Import failed": "Import nie powiódł się"
 }
diff --git a/apps/readest-app/public/locales/pt/translation.json b/apps/readest-app/public/locales/pt/translation.json
index 2db71aa8..bb3a004c 100644
--- a/apps/readest-app/public/locales/pt/translation.json
+++ b/apps/readest-app/public/locales/pt/translation.json
@@ -1081,5 +1081,6 @@
   "Decrease font size": "Diminuir tamanho da fonte",
   "Increase font size": "Aumentar tamanho da fonte",
   "Focus": "Foco",
-  "Theme color": "Cor do tema"
+  "Theme color": "Cor do tema",
+  "Import failed": "Falha na importação"
 }
diff --git a/apps/readest-app/public/locales/ru/translation.json b/apps/readest-app/public/locales/ru/translation.json
index 78ae39b3..359a5524 100644
--- a/apps/readest-app/public/locales/ru/translation.json
+++ b/apps/readest-app/public/locales/ru/translation.json
@@ -1093,5 +1093,6 @@
   "Decrease font size": "Уменьшить размер шрифта",
   "Increase font size": "Увеличить размер шрифта",
   "Focus": "Фокус",
-  "Theme color": "Цвет темы"
+  "Theme color": "Цвет темы",
+  "Import failed": "Ошибка импорта"
 }
diff --git a/apps/readest-app/public/locales/si/translation.json b/apps/readest-app/public/locales/si/translation.json
index 65ec4412..3354210c 100644
--- a/apps/readest-app/public/locales/si/translation.json
+++ b/apps/readest-app/public/locales/si/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "අකුරු ප්‍රමාණය අඩු කරන්න",
   "Increase font size": "අකුරු ප්‍රමාණය වැඩි කරන්න",
   "Focus": "අවධානය",
-  "Theme color": "තේමා වර්ණය"
+  "Theme color": "තේමා වර්ණය",
+  "Import failed": "ආයාත කිරීම අසාර්ථකයි"
 }
diff --git a/apps/readest-app/public/locales/sl/translation.json b/apps/readest-app/public/locales/sl/translation.json
index 65d50353..e008e6d3 100644
--- a/apps/readest-app/public/locales/sl/translation.json
+++ b/apps/readest-app/public/locales/sl/translation.json
@@ -1093,5 +1093,6 @@
   "Decrease font size": "Pomanjšaj pisavo",
   "Increase font size": "Povečaj pisavo",
   "Focus": "Fokus",
-  "Theme color": "Barva teme"
+  "Theme color": "Barva teme",
+  "Import failed": "Uvoz ni uspel"
 }
diff --git a/apps/readest-app/public/locales/sv/translation.json b/apps/readest-app/public/locales/sv/translation.json
index d0b5d70c..ba6b9bf8 100644
--- a/apps/readest-app/public/locales/sv/translation.json
+++ b/apps/readest-app/public/locales/sv/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "Minska teckenstorlek",
   "Increase font size": "Öka teckenstorlek",
   "Focus": "Fokus",
-  "Theme color": "Temafärg"
+  "Theme color": "Temafärg",
+  "Import failed": "Importen misslyckades"
 }
diff --git a/apps/readest-app/public/locales/ta/translation.json b/apps/readest-app/public/locales/ta/translation.json
index bbff1762..8e369db0 100644
--- a/apps/readest-app/public/locales/ta/translation.json
+++ b/apps/readest-app/public/locales/ta/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "எழுத்துரு அளவைக் குறை",
   "Increase font size": "எழுத்துரு அளவை அதிகரி",
   "Focus": "குவியம்",
-  "Theme color": "தீம் நிறம்"
+  "Theme color": "தீம் நிறம்",
+  "Import failed": "இறக்குமதி தோல்வி"
 }
diff --git a/apps/readest-app/public/locales/th/translation.json b/apps/readest-app/public/locales/th/translation.json
index f01dc969..8c5b9b4a 100644
--- a/apps/readest-app/public/locales/th/translation.json
+++ b/apps/readest-app/public/locales/th/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "ลดขนาดตัวอักษร",
   "Increase font size": "เพิ่มขนาดตัวอักษร",
   "Focus": "โฟกัส",
-  "Theme color": "สีธีม"
+  "Theme color": "สีธีม",
+  "Import failed": "นำเข้าล้มเหลว"
 }
diff --git a/apps/readest-app/public/locales/tr/translation.json b/apps/readest-app/public/locales/tr/translation.json
index 0236def7..6c4f0fb6 100644
--- a/apps/readest-app/public/locales/tr/translation.json
+++ b/apps/readest-app/public/locales/tr/translation.json
@@ -1069,5 +1069,6 @@
   "Decrease font size": "Yazı tipi boyutunu küçült",
   "Increase font size": "Yazı tipi boyutunu büyüt",
   "Focus": "Odak",
-  "Theme color": "Tema rengi"
+  "Theme color": "Tema rengi",
+  "Import failed": "İçe aktarma başarısız"
 }
diff --git a/apps/readest-app/public/locales/uk/translation.json b/apps/readest-app/public/locales/uk/translation.json
index a170c1e9..5089b906 100644
--- a/apps/readest-app/public/locales/uk/translation.json
+++ b/apps/readest-app/public/locales/uk/translation.json
@@ -1093,5 +1093,6 @@
   "Decrease font size": "Зменшити розмір шрифту",
   "Increase font size": "Збільшити розмір шрифту",
   "Focus": "Фокус",
-  "Theme color": "Колір теми"
+  "Theme color": "Колір теми",
+  "Import failed": "Помилка імпорту"
 }
diff --git a/apps/readest-app/public/locales/vi/translation.json b/apps/readest-app/public/locales/vi/translation.json
index 4066959f..f9cded9c 100644
--- a/apps/readest-app/public/locales/vi/translation.json
+++ b/apps/readest-app/public/locales/vi/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "Giảm cỡ chữ",
   "Increase font size": "Tăng cỡ chữ",
   "Focus": "Tiêu điểm",
-  "Theme color": "Màu chủ đề"
+  "Theme color": "Màu chủ đề",
+  "Import failed": "Nhập thất bại"
 }
diff --git a/apps/readest-app/public/locales/zh-CN/translation.json b/apps/readest-app/public/locales/zh-CN/translation.json
index f486900b..293c1d3c 100644
--- a/apps/readest-app/public/locales/zh-CN/translation.json
+++ b/apps/readest-app/public/locales/zh-CN/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "缩小字号",
   "Increase font size": "放大字号",
   "Focus": "焦点",
-  "Theme color": "主题颜色"
+  "Theme color": "主题颜色",
+  "Import failed": "导入失败"
 }
diff --git a/apps/readest-app/public/locales/zh-TW/translation.json b/apps/readest-app/public/locales/zh-TW/translation.json
index 72650fcb..e1e930c6 100644
--- a/apps/readest-app/public/locales/zh-TW/translation.json
+++ b/apps/readest-app/public/locales/zh-TW/translation.json
@@ -1057,5 +1057,6 @@
   "Decrease font size": "縮小字型",
   "Increase font size": "放大字型",
   "Focus": "焦點",
-  "Theme color": "主題顏色"
+  "Theme color": "主題顏色",
+  "Import failed": "匯入失敗"
 }
diff --git a/apps/readest-app/src/app/library/page.tsx b/apps/readest-app/src/app/library/page.tsx
index 45a2154e..a03fd671 100644
--- a/apps/readest-app/src/app/library/page.tsx
+++ b/apps/readest-app/src/app/library/page.tsx
@@ -12,6 +12,7 @@ import { Book } from '@/types/book';
 import { AppService, DeleteAction } from '@/types/system';
 import { navigateToLibrary, navigateToReader } from '@/utils/nav';
 import { formatAuthors, formatTitle, getPrimaryLanguage, listFormater } from '@/utils/book';
+import { getImportErrorMessage } from '@/services/errors';
 import { eventDispatcher } from '@/utils/event';
 import { ProgressPayload } from '@/utils/transfer';
 import { throttle } from '@/utils/throttle';
@@ -495,14 +496,6 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
     const { library } = useLibraryStore.getState();
     const failedImports: Array<{ filename: string; errorMessage: string }> = [];
     const successfulImports: string[] = [];
-    const errorMap: [string, string][] = [
-      ['No chapters detected', _('No chapters detected')],
-      ['Failed to parse EPUB', _('Failed to parse the EPUB file')],
-      ['Unsupported format', _('This book format is not supported')],
-      ['Failed to open file', _('Failed to open the book file')],
-      ['Invalid or empty book file', _('The book file is empty')],
-      ['Unsupported or corrupted book file', _('The book file is corrupted')],
-    ];
 
     const processFile = async (selectedFile: SelectedFile): Promise<Book | null> => {
       const file = selectedFile.file || selectedFile.path;
@@ -530,10 +523,7 @@ const LibraryPageContent = ({ searchParams }: { searchParams: ReadonlyURLSearchP
       } catch (error) {
         const filename = typeof file === 'string' ? file : file.name;
         const baseFilename = getFilename(filename);
-        const errorMessage =
-          error instanceof Error
-            ? errorMap.find(([str]) => error.message.includes(str))?.[1] || error.message
-            : '';
+        const errorMessage = error instanceof Error ? _(getImportErrorMessage(error.message)) : '';
         failedImports.push({ filename: baseFilename, errorMessage });
         console.error('Failed to import book:', filename, error);
         return null;
diff --git a/apps/readest-app/src/app/opds/components/PublicationView.tsx b/apps/readest-app/src/app/opds/components/PublicationView.tsx
index 1c7478f0..f9e3ed35 100644
--- a/apps/readest-app/src/app/opds/components/PublicationView.tsx
+++ b/apps/readest-app/src/app/opds/components/PublicationView.tsx
@@ -9,6 +9,7 @@ import { OPDSLink, OPDSPublication, REL, SYMBOL } from '@/types/opds';
 import { useTranslation } from '@/hooks/useTranslation';
 import { getFileExtFromMimeType } from '@/libs/document';
 import { formatDate, formatLanguage } from '@/utils/book';
+import { getImportErrorMessage, ImportError } from '@/services/errors';
 import { eventDispatcher } from '@/utils/event';
 import { navigateToReader } from '@/utils/nav';
 import { CachedImage } from '@/components/CachedImage';
@@ -96,10 +97,19 @@ export function PublicationView({
       eventDispatcher.dispatch('toast', { type: 'success', message: _('Download completed') });
     } catch (error) {
       console.error('Download failed:', error);
-      eventDispatcher.dispatch('toast', {
-        type: 'error',
-        message: _('Download failed') + `:\n${href}`,
-      });
+      if (error instanceof ImportError) {
+        const friendlyMsg = _(getImportErrorMessage(error.message));
+        eventDispatcher.dispatch('toast', {
+          type: 'error',
+          message: _('Import failed') + `:\n${friendlyMsg}`,
+          timeout: 5000,
+        });
+      } else {
+        eventDispatcher.dispatch('toast', {
+          type: 'error',
+          message: _('Download failed') + `:\n${href}`,
+        });
+      }
     } finally {
       setDownloading(false);
       setProgress(null);
diff --git a/apps/readest-app/src/app/opds/page.tsx b/apps/readest-app/src/app/opds/page.tsx
index 57c29a87..141845c0 100644
--- a/apps/readest-app/src/app/opds/page.tsx
+++ b/apps/readest-app/src/app/opds/page.tsx
@@ -36,6 +36,7 @@ import {
   needsProxy,
   probeFilename,
 } from './utils/opdsReq';
+import { ImportError } from '@/services/errors';
 import { READEST_OPDS_USER_AGENT } from '@/services/constants';
 import { FeedView } from './components/FeedView';
 import { PublicationView } from './components/PublicationView';
@@ -463,15 +464,20 @@ export default function BrowserPage() {
           }
 
           const { library, setLibrary } = useLibraryStore.getState();
-          const book = await appService.importBook(dstFilePath, library);
-          if (user && book && !book.uploadedAt && settings.autoUpload) {
-            setTimeout(() => {
-              transferManager.queueUpload(book);
-            }, 3000);
+          try {
+            const book = await appService.importBook(dstFilePath, library);
+            if (user && book && !book.uploadedAt && settings.autoUpload) {
+              setTimeout(() => {
+                transferManager.queueUpload(book);
+              }, 3000);
+            }
+            setLibrary(library);
+            appService.saveLibraryBooks(library);
+            return book;
+          } catch (importError) {
+            console.error('Import error:', importError);
+            throw new ImportError(importError);
           }
-          setLibrary(library);
-          appService.saveLibraryBooks(library);
-          return book;
         }
       } catch (e) {
         console.error('Download error:', e);
diff --git a/apps/readest-app/src/services/appService.ts b/apps/readest-app/src/services/appService.ts
index cc031e49..066e753b 100644
--- a/apps/readest-app/src/services/appService.ts
+++ b/apps/readest-app/src/services/appService.ts
@@ -80,7 +80,7 @@ import {
 import { ClosableFile } from '@/utils/file';
 import { ProgressHandler } from '@/utils/transfer';
 import { TxtToEpubConverter } from '@/utils/txt';
-import { BOOK_FILE_NOT_FOUND_ERROR } from './errors';
+import { BookFileNotFoundError } from './errors';
 import { CustomTextureInfo } from '@/styles/textures';
 import { CustomFont, CustomFontInfo } from '@/styles/fonts';
 import { parseFontInfo } from '@/utils/font';
@@ -395,7 +395,7 @@ export abstract class BaseAppService implements AppService {
           loadedBook.metadata.title = getBaseFilename(filename);
         }
       } catch (error) {
-        throw new Error(`Failed to open the book: ${(error as Error).message || error}`);
+        throw new Error(`Failed to open the book file: ${(error as Error).message || error}`);
       }
 
       const hash = await partialMD5(fileobj);
@@ -769,10 +769,10 @@ export abstract class BaseAppService implements AppService {
         if (bookFile) {
           file = await this.fs.openFile(`${bookDir}/${bookFile.path}`, 'Books');
         } else {
-          throw new Error(BOOK_FILE_NOT_FOUND_ERROR);
+          throw new BookFileNotFoundError();
         }
       } else {
-        throw new Error(BOOK_FILE_NOT_FOUND_ERROR);
+        throw new BookFileNotFoundError();
       }
     }
     return { book, file };
diff --git a/apps/readest-app/src/services/errors.ts b/apps/readest-app/src/services/errors.ts
index 5f23ae25..784c32ac 100644
--- a/apps/readest-app/src/services/errors.ts
+++ b/apps/readest-app/src/services/errors.ts
@@ -1 +1,30 @@
-export const BOOK_FILE_NOT_FOUND_ERROR = 'Book file not found';
+import { stubTranslation as _ } from '@/utils/misc';
+
+export class BookFileNotFoundError extends Error {
+  constructor() {
+    super('Book file not found');
+    this.name = 'BookFileNotFoundError';
+  }
+}
+
+export class ImportError extends Error {
+  constructor(cause: unknown) {
+    const msg = cause instanceof Error ? cause.message : String(cause);
+    super(msg);
+    this.name = 'ImportError';
+  }
+}
+
+const IMPORT_ERROR_MAP: [string, string][] = [
+  ['No chapters detected', _('No chapters detected')],
+  ['Failed to parse EPUB', _('Failed to parse the EPUB file')],
+  ['Unsupported format', _('This book format is not supported')],
+  ['Failed to open file', _('Failed to open the book file')],
+  ['Invalid or empty book file', _('The book file is empty')],
+  ['Unsupported or corrupted book file', _('The book file is corrupted')],
+];
+
+export const getImportErrorMessage = (errorMsg: string): string => {
+  const match = IMPORT_ERROR_MAP.find(([str]) => errorMsg.includes(str));
+  return match ? match[1] : errorMsg;
+};