diff --git a/frontend/package-lock.json b/frontend/package-lock.json
index c9e943f..e2017de 100644
--- a/frontend/package-lock.json
+++ b/frontend/package-lock.json
@@ -9,8 +9,6 @@
       "version": "0.1.0",
       "dependencies": {
         "@types/node": "^16.18.0",
-        "@types/react": "^18.2.0",
-        "@types/react-dom": "^18.2.0",
         "autoprefixer": "^10.4.0",
         "axios": "^1.6.0",
         "date-fns": "^2.30.0",
@@ -26,7 +24,9 @@
         "typescript": "^4.9.0"
       },
       "devDependencies": {
-        "@types/jest": "^27.5.0"
+        "@types/jest": "^27.5.0",
+        "@types/react": "^19.2.0",
+        "@types/react-dom": "^19.2.0"
       }
     },
     "node_modules/@alloc/quick-lru": {
@@ -3703,12 +3703,6 @@
       "integrity": "sha512-+68kP9yzs4LMp7VNh8gdzMSPZFL44MLGqiHWvttYJe+6qnuVr4Ek9wSBQoveqY/r+LwjCcU29kNVkidwim+kYA==",
       "license": "MIT"
     },
-    "node_modules/@types/prop-types": {
-      "version": "15.7.15",
-      "resolved": "https://registry.npmjs.org/@types/prop-types/-/prop-types-15.7.15.tgz",
-      "integrity": "sha512-F6bEyamV9jKGAFBEmlQnesRPGOQqS2+Uwi0Em15xenOxHaf2hv6L8YCVn3rPdPJOiJfPiCnLIRyvwVaqMY3MIw==",
-      "license": "MIT"
-    },
     "node_modules/@types/q": {
       "version": "1.5.8",
       "resolved": "https://registry.npmjs.org/@types/q/-/q-1.5.8.tgz",
@@ -3728,22 +3722,23 @@
       "license": "MIT"
     },
     "node_modules/@types/react": {
-      "version": "18.3.25",
-      "resolved": "https://registry.npmjs.org/@types/react/-/react-18.3.25.tgz",
-      "integrity": "sha512-oSVZmGtDPmRZtVDqvdKUi/qgCsWp5IDY29wp8na8Bj4B3cc99hfNzvNhlMkVVxctkAOGUA3Km7MMpBHAnWfcIA==",
+      "version": "19.2.0",
+      "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.0.tgz",
+      "integrity": "sha512-1LOH8xovvsKsCBq1wnT4ntDUdCJKmnEakhsuoUSy6ExlHCkGP2hqnatagYTgFk6oeL0VU31u7SNjunPN+GchtA==",
+      "dev": true,
       "license": "MIT",
       "dependencies": {
-        "@types/prop-types": "*",
         "csstype": "^3.0.2"
       }
     },
     "node_modules/@types/react-dom": {
-      "version": "18.3.7",
-      "resolved": "https://registry.npmjs.org/@types/react-dom/-/react-dom-18.3.7.tgz",
-      "integrity": "sha512-MEe3UeoENYVFXzoXEWsvcpg6ZvlrFNlOQ7EOsvhI3CfAXwzPfO8Qwuxd40nepsYKqyyVQnTdEfv68q91yLcKrQ==",
+      "version": "19.2.0",
+      "resolved": "https://registry.npmjs.org/@types/react-dom/-/react-dom-19.2.0.tgz",
+      "integrity": "sha512-brtBs0MnE9SMx7px208g39lRmC5uHZs96caOJfTjFcYSLHNamvaSMfJNagChVNkup2SdtOxKX1FDBkRSJe1ZAg==",
+      "dev": true,
       "license": "MIT",
       "peerDependencies": {
-        "@types/react": "^18.0.0"
+        "@types/react": "^19.2.0"
       }
     },
     "node_modules/@types/resolve": {
@@ -6348,6 +6343,7 @@
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/csstype/-/csstype-3.1.3.tgz",
       "integrity": "sha512-M1uQkMl8rQK/szD0LNhtqxIPLpimGm8sOBwU7lLnCpSbTyY3yeU1Vc7l4KT5zT4s/yOxHH5O7tIuuLOCnLADRw==",
+      "dev": true,
       "license": "MIT"
     },
     "node_modules/damerau-levenshtein": {
diff --git a/frontend/package.json b/frontend/package.json
index d8b03be..d39c6c0 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -4,21 +4,19 @@
   "private": true,
   "dependencies": {
     "@types/node": "^16.18.0",
-    "@types/react": "^18.2.0",
-    "@types/react-dom": "^18.2.0",
-    "react": "^18.2.0",
-    "react-dom": "^18.2.0",
-    "react-router-dom": "^6.8.0",
-    "react-scripts": "5.0.1",
-    "typescript": "^4.9.0",
+    "autoprefixer": "^10.4.0",
     "axios": "^1.6.0",
-    "react-hook-form": "^7.48.0",
-    "react-query": "^3.39.0",
     "date-fns": "^2.30.0",
     "lucide-react": "^0.294.0",
+    "postcss": "^8.4.0",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-hook-form": "^7.48.0",
+    "react-query": "^3.39.0",
+    "react-router-dom": "^6.8.0",
+    "react-scripts": "5.0.1",
     "tailwindcss": "^3.3.0",
-    "autoprefixer": "^10.4.0",
-    "postcss": "^8.4.0"
+    "typescript": "^4.9.0"
   },
   "scripts": {
     "start": "react-scripts start",
@@ -45,7 +43,9 @@
     ]
   },
   "devDependencies": {
-    "@types/jest": "^27.5.0"
+    "@types/jest": "^27.5.0",
+    "@types/react": "^19.2.0",
+    "@types/react-dom": "^19.2.0"
   },
   "proxy": "http://localhost:8080"
 }
diff --git a/frontend/src/components/CounterDetail.tsx b/frontend/src/components/CounterDetail.tsx
index d431bb9..03cca99 100644
--- a/frontend/src/components/CounterDetail.tsx
+++ b/frontend/src/components/CounterDetail.tsx
@@ -222,13 +222,13 @@ export const CounterDetail: React.FC = () => {
           Recent Entries
         </h2>
         
-        {entries.length === 0 ? (
+        {(entries?.length || 0) === 0 ? (
           <div className="text-center py-8 text-gray-500">
             No entries yet. Start by incrementing your counter!
           </div>
         ) : (
           <div className="space-y-3">
-            {entries.slice(0, 10).map((entry) => (
+            {entries?.slice(0, 10).map((entry) => (
               <div
                 key={entry.id}
                 className="flex justify-between items-center py-2 px-4 bg-gray-50 rounded-lg"
diff --git a/frontend/src/components/Dashboard.tsx b/frontend/src/components/Dashboard.tsx
index f17c9dc..01bf439 100644
--- a/frontend/src/components/Dashboard.tsx
+++ b/frontend/src/components/Dashboard.tsx
@@ -17,9 +17,9 @@ export const Dashboard: React.FC = () => {
     searchCounters(query);
   };
 
-  const totalCounters = counters.length;
-  const totalValue = counters.reduce((sum, counter) => sum + counter.total_value, 0);
-  const todayValue = counters.reduce((sum, counter) => sum + counter.today_value, 0);
+  const totalCounters = counters?.length || 0;
+  const totalValue = counters?.reduce((sum, counter) => sum + counter.total_value, 0) || 0;
+  const todayValue = counters?.reduce((sum, counter) => sum + counter.today_value, 0) || 0;
 
   if (error) {
     return (
@@ -109,7 +109,7 @@ export const Dashboard: React.FC = () => {
         <div className="flex justify-center items-center py-12">
           <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-primary-600"></div>
         </div>
-      ) : counters.length === 0 ? (
+      ) : (counters?.length || 0) === 0 ? (
         <div className="text-center py-12">
           <TrendingUp className="mx-auto h-12 w-12 text-gray-400" />
           <h3 className="mt-2 text-sm font-medium text-gray-900">No counters</h3>
@@ -128,7 +128,7 @@ export const Dashboard: React.FC = () => {
         </div>
       ) : (
         <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
-          {counters.map((counter) => (
+          {counters?.map((counter) => (
             <CounterCard key={counter.id} counter={counter} />
           ))}
         </div>
diff --git a/frontend/src/hooks/useCounters.tsx b/frontend/src/hooks/useCounters.tsx
index d0b5c82..46fa15c 100644
--- a/frontend/src/hooks/useCounters.tsx
+++ b/frontend/src/hooks/useCounters.tsx
@@ -110,7 +110,7 @@ export const useCounters = () => {
     } else {
       // Increment anonymous counter
       const today = localStorageService.getTodayString();
-      const counter = anonymousCounters.find(c => c.id === id);
+      const counter = anonymousCounters.find((c: AnonymousCounter) => c.id === id);
       if (counter) {
         const newTotal = counter.total_value + value;
         const newEntries = { ...counter.entries };
@@ -146,9 +146,9 @@ export const useCounters = () => {
   // Convert anonymous counters to CounterWithStats format for consistent UI
   const getDisplayCounters = (): CounterWithStats[] => {
     if (isAuthenticated) {
-      return counters;
+      return counters || [];
     } else {
-      return anonymousCounters.map(counter => ({
+      return (anonymousCounters || []).map((counter: AnonymousCounter) => ({
         id: parseInt(counter.id), // Convert string ID to number for display
         name: counter.name,
         description: counter.description,
@@ -156,23 +156,23 @@ export const useCounters = () => {
         updated_at: counter.updated_at,
         total_value: counter.total_value,
         today_value: counter.entries[localStorageService.getTodayString()] || 0,
-        week_value: Object.entries(counter.entries)
-          .filter(([date]) => {
+        week_value: Object.keys(counter.entries)
+          .filter((date) => {
             const entryDate = new Date(date);
             const weekAgo = new Date();
             weekAgo.setDate(weekAgo.getDate() - 7);
             return entryDate >= weekAgo;
           })
-          .reduce((sum, [, value]) => sum + (value as number), 0),
-        month_value: Object.entries(counter.entries)
-          .filter(([date]) => {
+          .reduce((sum, date) => sum + (counter.entries[date] as number), 0),
+        month_value: Object.keys(counter.entries)
+          .filter((date) => {
             const entryDate = new Date(date);
             const monthAgo = new Date();
             monthAgo.setMonth(monthAgo.getMonth() - 1);
             return entryDate >= monthAgo;
           })
-          .reduce((sum, [, value]) => sum + (value as number), 0),
-        entry_count: Object.values(counter.entries).reduce((sum: number, value: unknown) => sum + Math.abs(value as number), 0),
+          .reduce((sum, date) => sum + (counter.entries[date] as number), 0),
+        entry_count: Object.keys(counter.entries).reduce((sum: number, date: string) => sum + Math.abs(counter.entries[date] as number), 0),
       }));
     }
   };