diff --git a/src/App.vue b/src/App.vue
index 530fbcb..9a3db84 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -1,15 +1,26 @@
 <script setup lang="ts">
+import { defineAsyncComponent, onUnmounted, ref, watch } from 'vue';
 import RequestPanel from './components/RequestPanel.vue';
 import ResponsePanel from './components/ResponsePanel.vue';
 import Sidebar from './components/Sidebar.vue';
-import SettingsModal from './components/SettingsModal.vue';
-import { ref, onUnmounted } from 'vue';
+
+const SettingsModal = defineAsyncComponent(() => import('./components/SettingsModal.vue'));
+const PANEL_HEIGHT_STORAGE_KEY = 'topPanelHeight';
+const DEFAULT_TOP_PANEL_HEIGHT = 50;
+
+const clampPanelHeight = (value: number) => {
+  if (Number.isNaN(value)) return DEFAULT_TOP_PANEL_HEIGHT;
+  return Math.min(80, Math.max(20, value));
+};
 
 const showSettings = ref(false);
-const topPanelHeight = ref(50); // Percentage
+const topPanelHeight = ref(
+  clampPanelHeight(Number(localStorage.getItem(PANEL_HEIGHT_STORAGE_KEY)) || DEFAULT_TOP_PANEL_HEIGHT)
+);
 const isDragging = ref(false);
 
-const startDrag = () => {
+const startDrag = (event: MouseEvent) => {
+  event.preventDefault();
   isDragging.value = true;
   window.addEventListener('mousemove', onDrag);
   window.addEventListener('mouseup', stopDrag);
@@ -19,13 +30,8 @@ const onDrag = (e: MouseEvent) => {
   if (!isDragging.value) return;
   
   const containerHeight = window.innerHeight;
-  let newPercentage = (e.clientY / containerHeight) * 100;
-  
-  // Clamp between 20% and 80%
-  if (newPercentage < 20) newPercentage = 20;
-  if (newPercentage > 80) newPercentage = 80;
-  
-  topPanelHeight.value = newPercentage;
+  const newPercentage = (e.clientY / containerHeight) * 100;
+  topPanelHeight.value = clampPanelHeight(newPercentage);
 };
 
 const stopDrag = () => {
@@ -38,6 +44,10 @@ onUnmounted(() => {
   window.removeEventListener('mousemove', onDrag);
   window.removeEventListener('mouseup', stopDrag);
 });
+
+watch(topPanelHeight, (value) => {
+  localStorage.setItem(PANEL_HEIGHT_STORAGE_KEY, clampPanelHeight(value).toString());
+});
 </script>
 
 <template>
diff --git a/src/components/CodeEditor.vue b/src/components/CodeEditor.vue
new file mode 100644
index 0000000..2e8d376
--- /dev/null
+++ b/src/components/CodeEditor.vue
@@ -0,0 +1,65 @@
+<script setup lang="ts">
+import { computed } from 'vue';
+import { Codemirror } from 'vue-codemirror';
+import { json } from '@codemirror/lang-json';
+import { oneDark } from '@codemirror/theme-one-dark';
+import { EditorView } from '@codemirror/view';
+import { useSettingsStore } from '../stores/settingsStore';
+
+const props = withDefaults(defineProps<{
+  modelValue?: string;
+  placeholder?: string;
+  readOnly?: boolean;
+  language?: 'json' | 'text';
+}>(), {
+  modelValue: '',
+  placeholder: '',
+  readOnly: false,
+  language: 'text',
+});
+
+const emit = defineEmits<{
+  'update:modelValue': [value: string];
+}>();
+
+const settings = useSettingsStore();
+
+const extensions = computed(() => {
+  const theme = EditorView.theme({
+    '&': {
+      backgroundColor: 'transparent !important',
+      height: '100%',
+    },
+    '.cm-content, .cm-gutter': {
+      fontFamily: `${settings.editorFontFamily} !important`,
+    },
+    '.cm-gutters': {
+      backgroundColor: 'transparent !important',
+    },
+  });
+
+  return [
+    oneDark,
+    theme,
+    ...(props.language === 'json' ? [json()] : []),
+    ...(props.readOnly ? [EditorView.editable.of(false)] : []),
+  ];
+});
+</script>
+
+<template>
+  <Codemirror
+    :model-value="props.modelValue"
+    :placeholder="props.placeholder"
+    :style="{
+      height: '100%',
+      fontSize: settings.editorFontSize + 'px',
+      fontFamily: settings.editorFontFamily,
+    }"
+    :autofocus="false"
+    :indent-with-tab="true"
+    :tab-size="2"
+    :extensions="extensions"
+    @update:model-value="emit('update:modelValue', $event)"
+  />
+</template>
diff --git a/src/components/RequestPanel.vue b/src/components/RequestPanel.vue
index c8912ef..0060fb8 100644
--- a/src/components/RequestPanel.vue
+++ b/src/components/RequestPanel.vue
@@ -1,55 +1,32 @@
 <script setup lang="ts">
-import { ref, computed } from 'vue';
+import { defineAsyncComponent, ref } from 'vue';
 import { useRequestStore } from '../stores/requestStore';
-import { useSettingsStore } from '../stores/settingsStore';
 import KeyValueEditor from './KeyValueEditor.vue';
 import AuthPanel from './AuthPanel.vue';
 import CustomSelect from './CustomSelect.vue';
 import { invoke } from '@tauri-apps/api/core';
-import { Codemirror } from 'vue-codemirror';
-import { json } from '@codemirror/lang-json';
-import { oneDark } from '@codemirror/theme-one-dark';
-import { EditorView } from '@codemirror/view';
 import { Play, Loader2 } from 'lucide-vue-next';
 
+const CodeEditor = defineAsyncComponent(() => import('./CodeEditor.vue'));
 const store = useRequestStore();
-const settings = useSettingsStore();
 const activeTab = ref('params');
 const isLoading = ref(false);
 
-const extensions = computed(() => {
-  const theme = EditorView.theme({
-    "&": { 
-      backgroundColor: "transparent !important", 
-      height: "100%",
-    },
-    ".cm-content, .cm-gutter": {
-      fontFamily: `${settings.editorFontFamily} !important`
-    },
-    ".cm-gutters": { 
-      backgroundColor: "transparent !important" 
-    }
-  });
-  
-  return [json(), oneDark, theme];
-});
-
 const methods = ['GET', 'POST', 'PUT', 'DELETE', 'PATCH', 'HEAD', 'OPTIONS'];
 
 const executeRequest = async () => {
   if (isLoading.value || !store.activeRequest.url) return;
   
   isLoading.value = true;
+  store.setRequestError(null);
   
   try {
-    // Prepare headers and params map
     const headers: Record<string, string> = {};
     store.activeRequest.headers.filter(h => h.enabled && h.key).forEach(h => headers[h.key] = h.value);
     
     const params: Record<string, string> = {};
     store.activeRequest.params.filter(p => p.enabled && p.key).forEach(p => params[p.key] = p.value);
 
-    // Execute
     const response: any = await invoke('execute_request', {
       method: store.activeRequest.method,
       url: store.activeRequest.url,
@@ -59,7 +36,7 @@ const executeRequest = async () => {
       auth: store.activeRequest.auth,
     });
 
-    // Update Store
+    store.setRequestError(null);
     store.activeRequest.response = {
         status: response.status,
         headers: response.headers,
@@ -68,12 +45,12 @@ const executeRequest = async () => {
         size: new Blob([response.body]).size
     };
 
-    // Add to history if successful
     store.addToHistory(store.activeRequest);
 
   } catch (error) {
     console.error(error);
-    alert('Request Failed: ' + error);
+    store.activeRequest.response = undefined;
+    store.setRequestError(String(error));
   } finally {
     isLoading.value = false;
   }
@@ -109,6 +86,13 @@ const executeRequest = async () => {
       </button>
     </div>
 
+    <div
+      v-if="store.requestError"
+      class="mx-4 mt-4 rounded-lg border border-rose-500/30 bg-rose-500/10 px-3 py-2 text-sm text-rose-200"
+    >
+      {{ store.requestError }}
+    </div>
+
     <!-- Configuration Tabs -->
     <div class="flex border-b border-slate-800">
       <button 
@@ -137,18 +121,10 @@ const executeRequest = async () => {
             />
         </KeepAlive>
         <div v-if="activeTab === 'body'" class="h-full w-full overflow-hidden">
-            <Codemirror
+            <CodeEditor
                 v-model="store.activeRequest.body"
                 placeholder="Request Body (JSON)"
-                :style="{ 
-                  height: '100%', 
-                  fontSize: settings.editorFontSize + 'px', 
-                  fontFamily: settings.editorFontFamily 
-                }"
-                :autofocus="true"
-                :indent-with-tab="true"
-                :tab-size="2"
-                :extensions="extensions"
+                language="json"
             />
         </div>
         <KeepAlive>
diff --git a/src/components/ResponsePanel.vue b/src/components/ResponsePanel.vue
index da336e2..654edca 100644
--- a/src/components/ResponsePanel.vue
+++ b/src/components/ResponsePanel.vue
@@ -1,16 +1,12 @@
 <script setup lang="ts">
-import { computed, ref } from 'vue';
+import { computed, defineAsyncComponent, ref } from 'vue';
 import { useRequestStore } from '../stores/requestStore';
-import { useSettingsStore } from '../stores/settingsStore';
-import { Codemirror } from 'vue-codemirror';
-import { json } from '@codemirror/lang-json';
-import { oneDark } from '@codemirror/theme-one-dark';
-import { EditorView } from '@codemirror/view';
 import { Clipboard, Check } from 'lucide-vue-next';
 
+const CodeEditor = defineAsyncComponent(() => import('./CodeEditor.vue'));
 const store = useRequestStore();
-const settings = useSettingsStore();
 const isCopied = ref(false);
+const activeTab = ref<'body' | 'headers'>('body');
 
 const isJsonResponse = computed(() => {
   const response = store.activeRequest.response;
@@ -29,26 +25,14 @@ const isJsonResponse = computed(() => {
   }
 });
 
-const extensions = computed(() => {
-  const theme = EditorView.theme({
-    "&": {
-      backgroundColor: "transparent !important",
-      height: "100%"
-    },
-    ".cm-content, .cm-gutter": {
-      fontFamily: `${settings.editorFontFamily} !important`
-    },
-    ".cm-gutters": {
-      backgroundColor: "transparent !important"
-    }
-  });
+const formattedHeaders = computed(() => {
+  const response = store.activeRequest.response;
+  if (!response) return '';
 
-  return [
-    oneDark,
-    theme,
-    EditorView.editable.of(false),
-    ...(isJsonResponse.value ? [json()] : []),
-  ];
+  return Object.entries(response.headers)
+    .sort(([keyA], [keyB]) => keyA.localeCompare(keyB))
+    .map(([key, value]) => `${key}: ${value}`)
+    .join('\n');
 });
 
 const formattedBody = computed(() => {
@@ -61,6 +45,10 @@ const formattedBody = computed(() => {
     }
 });
 
+const displayedContent = computed(() => (
+  activeTab.value === 'headers' ? formattedHeaders.value : formattedBody.value
+));
+
 const statusColor = computed(() => {
     const s = store.activeRequest.response?.status || 0;
     if (s >= 200 && s < 300) return 'text-emerald-400';
@@ -69,9 +57,9 @@ const statusColor = computed(() => {
 });
 
 const copyToClipboard = async () => {
-  if (!formattedBody.value) return;
+  if (!displayedContent.value) return;
   try {
-    await navigator.clipboard.writeText(formattedBody.value);
+    await navigator.clipboard.writeText(displayedContent.value);
     isCopied.value = true;
     setTimeout(() => {
       isCopied.value = false;
@@ -98,30 +86,50 @@ const copyToClipboard = async () => {
                     Size: <span class="text-slate-300">{{ (store.activeRequest.response.size / 1024).toFixed(2) }} KB</span>
                 </div>
             </div>
-            
-            <button 
-              @click="copyToClipboard"
-              class="p-1.5 text-slate-400 hover:text-indigo-400 hover:bg-indigo-500/10 rounded transition-colors"
-              title="Copy Body"
-            >
-               <Check v-if="isCopied" class="w-3.5 h-3.5" />
-               <Clipboard v-else class="w-3.5 h-3.5" />
-            </button>
+
+            <div class="flex items-center gap-2">
+              <div class="flex rounded-lg border border-slate-800 bg-slate-900 p-0.5">
+                <button
+                  @click="activeTab = 'body'"
+                  class="rounded-md px-2.5 py-1 transition-colors"
+                  :class="activeTab === 'body' ? 'bg-indigo-500/15 text-indigo-300' : 'text-slate-400 hover:text-slate-200'"
+                >
+                  Body
+                </button>
+                <button
+                  @click="activeTab = 'headers'"
+                  class="rounded-md px-2.5 py-1 transition-colors"
+                  :class="activeTab === 'headers' ? 'bg-indigo-500/15 text-indigo-300' : 'text-slate-400 hover:text-slate-200'"
+                >
+                  Headers
+                </button>
+              </div>
+
+              <button 
+                @click="copyToClipboard"
+                class="p-1.5 text-slate-400 hover:text-indigo-400 hover:bg-indigo-500/10 rounded transition-colors"
+                :title="activeTab === 'headers' ? 'Copy Headers' : 'Copy Body'"
+              >
+                 <Check v-if="isCopied" class="w-3.5 h-3.5" />
+                 <Clipboard v-else class="w-3.5 h-3.5" />
+              </button>
+            </div>
         </div>
         
         <!-- Output -->
         <div class="flex-1 overflow-hidden">
-            <Codemirror
-                :model-value="formattedBody"
-                :style="{ 
-                  height: '100%',
-                  fontSize: settings.editorFontSize + 'px', 
-                  fontFamily: settings.editorFontFamily 
-                }"
-                :extensions="extensions"
+            <CodeEditor
+                :model-value="displayedContent"
+                :language="activeTab === 'body' && isJsonResponse ? 'json' : 'text'"
+                :read-only="true"
             />
         </div>
     </div>
+    <div v-else-if="store.requestError" class="flex-1 flex items-center justify-center p-6">
+        <div class="max-w-2xl rounded-xl border border-rose-500/30 bg-rose-500/10 p-4 text-sm text-rose-200">
+          {{ store.requestError }}
+        </div>
+    </div>
     <div v-else class="flex-1 flex items-center justify-center text-slate-600 text-sm">
         No response yet
     </div>
diff --git a/src/stores/requestStore.ts b/src/stores/requestStore.ts
index f9ef713..afe1dcd 100644
--- a/src/stores/requestStore.ts
+++ b/src/stores/requestStore.ts
@@ -128,6 +128,7 @@ export const useRequestStore = defineStore('request', () => {
   // State
   const history = ref<RequestData[]>([]);
   const activeRequest = ref<RequestData>(createDefaultRequest());
+  const requestError = ref<string | null>(null);
 
   // Load history from local storage
   const savedHistory = localStorage.getItem('request_history');
@@ -169,6 +170,7 @@ export const useRequestStore = defineStore('request', () => {
 
   const resetActiveRequest = () => {
     activeRequest.value = createDefaultRequest();
+    requestError.value = null;
   };
 
   const loadRequest = (req: RequestData) => {
@@ -178,6 +180,11 @@ export const useRequestStore = defineStore('request', () => {
     if (loaded.headers.length === 0) loaded.headers.push(createEmptyKeyValue());
 
     activeRequest.value = loaded;
+    requestError.value = null;
+  };
+
+  const setRequestError = (message: string | null) => {
+    requestError.value = message;
   };
 
   // Watch and Save
@@ -188,10 +195,12 @@ export const useRequestStore = defineStore('request', () => {
   return {
     history,
     activeRequest,
+    requestError,
     addToHistory,
     clearHistory,
     deleteHistoryItem,
     loadRequest,
-    resetActiveRequest
+    resetActiveRequest,
+    setRequestError,
   };
 });
diff --git a/vite.config.ts b/vite.config.ts
index 812e61c..68579ad 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -7,6 +7,21 @@ const host = process.env.TAURI_DEV_HOST;
 // https://vite.dev/config/
 export default defineConfig(async () => ({
   plugins: [vue()],
+  build: {
+    rollupOptions: {
+      output: {
+        manualChunks: {
+          codemirror: [
+            'vue-codemirror',
+            '@codemirror/lang-json',
+            '@codemirror/theme-one-dark',
+            '@codemirror/view',
+          ],
+          vue: ['vue', 'pinia'],
+        },
+      },
+    },
+  },
 
   // Vite options tailored for Tauri development and only applied in `tauri dev` or `tauri build`
   //