diff --git a/src/index.tsx b/src/index.tsx
index 1d2fd1663e4e..813a3691b87d 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -7,7 +7,6 @@ import { AppContextProvider } from "./AppContext";
 import "./i18n";
 import { fetchDbFunc } from "./db";
 import * as serviceWorkerRegistration from "./serviceWorkerRegistration";
-import type { WarnUpMessageData } from "./typing";
 import ErrorBoundary from "./ErrorBoundary";
 import { CollectionContextProvider } from "./CollectionContext";
 import { ReactNativeContextProvider } from "./ReactNativeContext";
@@ -37,17 +36,8 @@ if (isHuman()) {
   // Target: render only if development or prerendering or in registered app or lazy loading page
   const prerenderStyle = document.querySelector("style[prerender]");
   const workboxPromise = serviceWorkerRegistration.register({
-    onUpdate: (workbox, skipWaiting) => {
+    onUpdate: (_, skipWaiting) => {
       skipWaiting();
-      const message: WarnUpMessageData = {
-        type: "WARN_UP_MAP_CACHE",
-        retinaDisplay:
-          (window.devicePixelRatio ||
-            // @ts-ignore: Property does not exist on type 'Screen'.
-            window.screen.deviceXDPI / window.screen.logicalXDPI) > 1,
-        zoomLevels: [14, 15],
-      };
-      workbox.messageSW(message);
     },
   });
   const fetchDb = fetchDbFunc();
diff --git a/src/pages/RouteEta.tsx b/src/pages/RouteEta.tsx
index 61734daa84bb..06890cd94ff8 100644
--- a/src/pages/RouteEta.tsx
+++ b/src/pages/RouteEta.tsx
@@ -7,7 +7,6 @@ import StopDialog from "../components/route-eta/StopDialog";
 import AppContext from "../AppContext";
 import { useTranslation } from "react-i18next";
 import { setSeoHeader, toProperCase, getDistance } from "../utils";
-import type { WarnUpMessageData } from "../typing";
 import StrSim from "string-similarity";
 import {
   Company,
@@ -25,7 +24,6 @@ const RouteEta = () => {
     db: { routeList, stopList, stopMap },
     updateSelectedRoute,
     energyMode,
-    workbox,
     geoPermission,
     geolocation,
   } = useContext(AppContext);
@@ -90,10 +88,10 @@ const RouteEta = () => {
   }, [panel, stops, defaultStopIdx]);
 
   const [isDialogOpen, setIsDialogOpen] = useState(false);
-  const dialogStop = useMemo(() => {
-    console.log(getDialogStops(co, stops, stopMap, stopIdx));
-    return getDialogStops(co, stops, stopMap, stopIdx);
-  }, [co, stopIdx, stopMap, stops]);
+  const dialogStop = useMemo(
+    () => getDialogStops(co, stops, stopMap, stopIdx),
+    [co, stopIdx, stopMap, stops]
+  );
 
   const { t, i18n } = useTranslation();
   const navigate = useNavigate();
@@ -202,23 +200,6 @@ const RouteEta = () => {
     t,
   ]);
 
-  useEffect(() => {
-    if (!energyMode && navigator.userAgent !== "prerendering") {
-      const message: WarnUpMessageData = {
-        type: "WARN_UP_MAP_CACHE",
-        retinaDisplay:
-          (window.devicePixelRatio ||
-            // @ts-ignore: Property does not exist on type 'Screen'.
-            window.screen.deviceXDPI / window.screen.logicalXDPI) > 1,
-        zoomLevels: [14, 15, 16, 17, 18],
-        stopList: getStops(co, stops)
-          .map((id) => stopList[id])
-          .filter((stop) => stop !== null && stop !== undefined),
-      };
-      workbox?.messageSW(message);
-    }
-  }, [co, energyMode, stopList, stops, workbox]);
-
   return (
     <>
       <input hidden id={id} />
diff --git a/src/service-worker.ts b/src/service-worker.ts
index cf1404e33fe8..3297497850cd 100644
--- a/src/service-worker.ts
+++ b/src/service-worker.ts
@@ -18,9 +18,6 @@ import {
   StrategyHandler,
 } from "workbox-strategies";
 import { CacheableResponsePlugin } from "workbox-cacheable-response";
-import { fetchEtaDb } from "hk-bus-eta";
-import { getTileListURL, isWarnUpMessageData } from "./utils";
-import type { StopListEntry } from "hk-bus-eta";
 
 declare var self: ServiceWorkerGlobalScope & typeof globalThis;
 clientsClaim();
@@ -133,52 +130,6 @@ registerRoute(
   })
 );
 
-const warnUpCache = async (
-  zoomLevels: Array<number>,
-  event: ExtendableEvent,
-  retina: boolean,
-  stopListInput?: Array<StopListEntry>
-) => {
-  try {
-    let stopList;
-    if (stopListInput === undefined) {
-      const eta = await fetchEtaDb();
-      stopList = Object.values(eta.stopList);
-    } else {
-      stopList = stopListInput;
-    }
-    await Promise.all(
-      zoomLevels.map(async (i) => {
-        const generate = function* () {
-          const list = getTileListURL(i, stopList, retina);
-          for (let k = 0; k < list.length; k = k + 1) {
-            yield mapCacheStrategy.handleAll({
-              event,
-              request: new Request(list[k], {}),
-            })[1];
-          }
-        };
-        const a = generate();
-        let result = a.next();
-        const pendingPromise: Set<Promise<void>> = new Set();
-        while (result.done !== true) {
-          const value = result.value;
-          pendingPromise.add(value);
-          value.then(() => pendingPromise.delete(value));
-          // limit pending fetch to 10
-          if (pendingPromise.size >= 10) {
-            await Promise.any(pendingPromise);
-          }
-          result = a.next();
-        }
-        return;
-      })
-    );
-  } catch (e) {
-    console.error("error on warn cache", e);
-  }
-};
-
 // This allows the web app to trigger skipWaiting via
 // registration.waiting.postMessage({type: 'SKIP_WAITING'})
 self.addEventListener("message", (event) => {
@@ -197,21 +148,4 @@ self.addEventListener("message", (event) => {
         )
       );
   }
-  const data: unknown = event.data;
-  if (isWarnUpMessageData(data)) {
-    console.log("warm up map cache", data);
-    const warnCache = async () => {
-      try {
-        await warnUpCache(
-          data.zoomLevels,
-          event,
-          data.retinaDisplay,
-          data.stopList
-        );
-      } catch (e) {
-        console.error("error on warn cache", e);
-      }
-    };
-    event.waitUntil(warnCache());
-  }
 });
diff --git a/src/typing.ts b/src/typing.ts
index a600d97b6d03..75187fc277ed 100644
--- a/src/typing.ts
+++ b/src/typing.ts
@@ -1,12 +1,3 @@
-import type { StopListEntry } from "hk-bus-eta";
-
-export interface WarnUpMessageData {
-  type: "WARN_UP_MAP_CACHE";
-  retinaDisplay: boolean;
-  zoomLevels: number[];
-  stopList?: StopListEntry[];
-}
-
 export interface DaySchedule {
   day: number;
   // use start, end only if allDay is false
diff --git a/src/utils.ts b/src/utils.ts
index 5dc0b0116559..c175bd6bc970 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,13 +1,6 @@
-import type {
-  Company,
-  EtaDb,
-  Location,
-  RouteList,
-  StopList,
-  StopListEntry,
-} from "hk-bus-eta";
+import type { Company, EtaDb, Location, RouteList, StopList } from "hk-bus-eta";
 import type { Location as GeoLocation } from "hk-bus-eta";
-import type { TransportType, WarnUpMessageData } from "./typing";
+import type { TransportType } from "./typing";
 import { isRouteAvaliable } from "./timetable";
 export const getDistance = (a: GeoLocation, b: GeoLocation) => {
   const R = 6371e3; // metres
@@ -229,56 +222,6 @@ export const binarySearch = <T>(
   return -m - 1;
 };
 
-interface TempEntry {
-  key: number;
-  x: number;
-  y: number;
-}
-
-export const getTileListURL = (
-  zoomLevel: number,
-  stopLists: Array<StopListEntry>,
-  retinaDisplay: boolean
-) => {
-  const high = 255 * (zoomLevel + 5) * (zoomLevel + 5);
-  const compare = (a: TempEntry, b: TempEntry) => b.key - a.key;
-  return stopLists
-    .map((stop) => {
-      const x = lon2tile(stop.location.lng, zoomLevel);
-      const y = lat2tile(stop.location.lat, zoomLevel);
-      return {
-        key: x * high + y,
-        x: x,
-        y: y,
-      };
-    })
-    .sort(compare)
-    .reduce((prev: TempEntry[], curr) => {
-      if (binarySearch(prev, curr, compare) < 0) {
-        prev.push(curr);
-      }
-      return prev;
-    }, [])
-    .flatMap((entry) => [
-      process.env.REACT_APP_OSM_PROVIDER_URL.replace(/\{s\}/g, "a")
-        .replace(/\{x\}/g, String(entry.x))
-        .replace(/\{y\}/g, String(entry.y))
-        .replace(/\{z\}/g, String(zoomLevel))
-        .replace(/\{r\}/g, retinaDisplay ? "@2x" : ""),
-      process.env.REACT_APP_OSM_PROVIDER_URL_DARK.replace(/\{s\}/g, "a")
-        .replace(/\{x\}/g, String(entry.x))
-        .replace(/\{y\}/g, String(entry.y))
-        .replace(/\{z\}/g, String(zoomLevel))
-        .replace(/\{r\}/g, retinaDisplay ? "@2x" : ""),
-    ]);
-};
-
-export const isWarnUpMessageData = (
-  value: unknown
-): value is WarnUpMessageData => {
-  return typeof value === "object" && value["type"] === "WARN_UP_MAP_CACHE";
-};
-
 export const checkAppInstalled = () => {
   if (window.matchMedia("(display-mode: standalone)").matches) return true;
   // @ts-ignore