diff --git a/src/i18n.ts b/src/i18n.ts
index b5085e5..97f8f07 100644
--- a/src/i18n.ts
+++ b/src/i18n.ts
@@ -8,35 +8,8 @@ import LanguageDetector from "i18next-browser-languagedetector";
 import ChainedBackend from "i18next-chained-backend";
 import LocalStorageBackend from "i18next-localstorage-backend";
 
-// eslint-disable-next-line @typescript-eslint/ban-ts-ignore
-// @ts-ignore
-i18n
-  .use(ChainedBackend)
-  .use(LanguageDetector)
-  .use(initReactI18next)
-  .init({
-    fallbackLng: "en-US",
-    debug: true,
-    ns: ["common", "application", "dashboard"],
-    load: "currentOnly",
-    defaultNS: "application",
-    interpolation: {
-      escapeValue: false,
-    },
-    backend: {
-      backends: process.env.NODE_ENV === "development" ? [Backend] : [LocalStorageBackend, Backend],
-      backendOptions: [
-        {
-          expirationTime: 7 * 24 * 60 * 60 * 1000, // 7 days
-          loadPath: "/locales/{{lng}}/{{ns}}.json",
-        },
-      ],
-    },
-  });
-
-i18n.on("languageChanged", (lng) => {
-  document.documentElement.setAttribute("lang", lng);
-});
+const isDev = process.env.NODE_ENV === "development";
+isDev && console.log("i18next: set to development mode, localStorage backend disabled.");
 
 export const languages = [
   {
@@ -85,4 +58,49 @@ export const languages = [
   },
 ];
 
+// eslint-disable-next-line @typescript-eslint/ban-ts-ignore
+// @ts-ignore
+i18n
+  .use(ChainedBackend)
+  .use(LanguageDetector)
+  .use(initReactI18next)
+  .init({
+    fallbackLng: languages[0].code,
+    supportedLngs: languages.map((l) => l.code),
+    debug: isDev,
+    ns: ["common", "application", "dashboard"],
+    load: "currentOnly",
+    defaultNS: "application",
+    interpolation: {
+      escapeValue: false,
+    },
+    backend: {
+      // https://www.i18next.com/how-to/caching#browser-caching-with-local-storage
+      // https://github.com/i18next/i18next-localstorage-backend#cache-backend-options
+      backends: isDev ? [Backend] : [LocalStorageBackend, Backend],
+      backendOptions: isDev
+        ? [
+            {
+              /* HttpApi */
+              loadPath: "/locales/{{lng}}/{{ns}}.json",
+            },
+          ]
+        : [
+            {
+              /* LocalStorageBackend */
+              expirationTime: 365 * 24 * 60 * 60 * 1000, // 365 days, cache managed by version control
+              defaultVersion: __BUILD_TIMESTAMP__,
+            },
+            {
+              /* HttpApi */
+              loadPath: "/locales/{{lng}}/{{ns}}.json",
+            },
+          ],
+    },
+  });
+
+i18n.on("languageChanged", (lng) => {
+  document.documentElement.setAttribute("lang", lng);
+});
+
 export default i18n;
diff --git a/vite.config.ts b/vite.config.ts
index 2b64e2f..4a014c7 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -21,7 +21,7 @@ export default defineConfig({
         navigateFallbackDenylist: [/^\/pdfviewer.html/, /^\/api\/(.+)/, /^\/f\/(.+)/, /^\/s\/(.+)/],
       },
       devOptions: {
-        enabled: true,
+        enabled: process.env.NODE_ENV !== "production",
       },
     }),
     viteStaticCopy({
@@ -58,6 +58,7 @@ export default defineConfig({
   ],
   define: {
     __ASSETS_VERSION__: JSON.stringify(process.env.npm_package_version),
+    __BUILD_TIMESTAMP__: JSON.stringify(Math.floor(Date.now())),
   },
   build: {
     outDir: "build", // keep same as v3 with minimal changes