diff --git a/app/[locale]/page.tsx b/app/[locale]/page.tsx
index b3cbff6b..8512dbbc 100644
--- a/app/[locale]/page.tsx
+++ b/app/[locale]/page.tsx
@@ -108,6 +108,7 @@ export default function Home() {
     selectedKeyword,
     selectKeyword,
     hasMoreEmails,
+    fetchTagCounts,
   } = useEmailStore();
 
   // Keyboard shortcuts handlers
@@ -299,6 +300,9 @@ export default function Home() {
             await fetchEmails(client);
           }
 
+          // Fetch tag counts
+          fetchTagCounts(client);
+
           // Setup push notifications after successful data load
           try {
             // Register state change callback
@@ -330,7 +334,7 @@ export default function Home() {
         client.closePushNotifications();
       }
     };
-  }, [isAuthenticated, client, mailboxes.length, fetchMailboxes, fetchEmails, fetchQuota, handleStateChange, setPushConnected]);
+  }, [isAuthenticated, client, mailboxes.length, fetchMailboxes, fetchEmails, fetchQuota, fetchTagCounts, handleStateChange, setPushConnected]);
 
   // Handle mark-as-read with delay based on settings
   useEffect(() => {
@@ -587,6 +591,9 @@ export default function Home() {
 
       // Refresh emails list to show color in list
       await fetchEmails(client, selectedMailbox);
+
+      // Refresh tag counts
+      fetchTagCounts(client);
     } catch (error) {
       console.error("Failed to set color tag:", error);
     }
diff --git a/components/layout/sidebar.tsx b/components/layout/sidebar.tsx
index 86576200..9c4859fc 100644
--- a/components/layout/sidebar.tsx
+++ b/components/layout/sidebar.tsx
@@ -34,6 +34,7 @@ import { useUIStore } from "@/stores/ui-store";
 import { useAuthStore } from "@/stores/auth-store";
 import { useVacationStore } from "@/stores/vacation-store";
 import { useSettingsStore, KEYWORD_PALETTE, KeywordDefinition } from "@/stores/settings-store";
+import { useEmailStore } from "@/stores/email-store";
 import { toast } from "@/stores/toast-store";
 import { debug } from "@/lib/debug";
 
@@ -227,11 +228,15 @@ function TagItem({
   isSelected,
   isCollapsed,
   onTagSelect,
+  totalCount,
+  unreadCount,
 }: {
   kw: KeywordDefinition;
   isSelected: boolean;
   isCollapsed: boolean;
   onTagSelect?: (keywordId: string | null) => void;
+  totalCount: number;
+  unreadCount: number;
 }) {
   const t = useTranslations('notifications');
   const palette = KEYWORD_PALETTE[kw.color];
@@ -272,7 +277,26 @@ function TagItem({
         title={isCollapsed ? kw.label : undefined}
       >
         <span className={cn("w-3 h-3 rounded-full flex-shrink-0", palette?.dot || "bg-gray-400", !isCollapsed && "mr-2")} />
-        {!isCollapsed && <span className="truncate">{kw.label}</span>}
+        {!isCollapsed && (
+          <>
+            <span className="truncate">{kw.label}</span>
+            <span className="flex items-center gap-1.5 ml-2 flex-shrink-0">
+              {unreadCount > 0 && (
+                <span className={cn(
+                  "text-xs rounded-full px-2 py-0.5 font-medium",
+                  isSelected
+                    ? "bg-primary text-primary-foreground"
+                    : "bg-foreground text-background"
+                )}>
+                  {unreadCount}
+                </span>
+              )}
+              <span className="text-xs text-muted-foreground tabular-nums">
+                {totalCount}
+              </span>
+            </span>
+          </>
+        )}
       </button>
     </div>
   );
@@ -321,6 +345,7 @@ export function Sidebar({
     } catch { return true; }
   });
   const emailKeywords = useSettingsStore(s => s.emailKeywords);
+  const tagCounts = useEmailStore(s => s.tagCounts);
   const t = useTranslations('sidebar');
 
   useEffect(() => {
@@ -532,6 +557,8 @@ export function Sidebar({
                       isSelected={isSelected}
                       isCollapsed={isCollapsed}
                       onTagSelect={onTagSelect}
+                      totalCount={tagCounts[kw.id]?.total ?? 0}
+                      unreadCount={tagCounts[kw.id]?.unread ?? 0}
                     />
                   );
                 })}
diff --git a/hooks/use-tag-drop.ts b/hooks/use-tag-drop.ts
index 2e80b487..c90c68c1 100644
--- a/hooks/use-tag-drop.ts
+++ b/hooks/use-tag-drop.ts
@@ -5,6 +5,7 @@ import { useEmailStore } from "@/stores/email-store";
 import { useAuthStore } from "@/stores/auth-store";
 import { useDragDropContext } from "@/contexts/drag-drop-context";
 
+
 interface UseTagDropOptions {
   tagId: string;
   onSuccess?: (count: number, tagLabel: string) => void;
@@ -25,7 +26,7 @@ interface UseTagDropReturn {
 export function useTagDrop({ tagId, onSuccess, onError }: UseTagDropOptions): UseTagDropReturn {
   const [isOver, setIsOver] = useState(false);
   const { client } = useAuthStore();
-  const { fetchEmails, selectedMailbox } = useEmailStore();
+  const { fetchEmails, fetchTagCounts, selectedMailbox } = useEmailStore();
   const { isDragging, endDrag } = useDragDropContext();
 
   const handleDragOver = useCallback((e: DragEvent<HTMLDivElement>) => {
@@ -93,6 +94,9 @@ export function useTagDrop({ tagId, onSuccess, onError }: UseTagDropOptions): Us
       // Refresh the email list
       await fetchEmails(client, selectedMailbox);
 
+      // Refresh tag counts
+      fetchTagCounts(client);
+
       onSuccess?.(emailIds.length, tagId);
     } catch (error) {
       console.error("Failed to tag emails:", error);
@@ -100,7 +104,7 @@ export function useTagDrop({ tagId, onSuccess, onError }: UseTagDropOptions): Us
     } finally {
       endDrag();
     }
-  }, [client, isDragging, tagId, fetchEmails, selectedMailbox, endDrag, onSuccess, onError]);
+  }, [client, isDragging, tagId, fetchEmails, fetchTagCounts, selectedMailbox, endDrag, onSuccess, onError]);
 
   return {
     dropHandlers: {
diff --git a/lib/jmap/client.ts b/lib/jmap/client.ts
index ecc79d83..0f5b3726 100644
--- a/lib/jmap/client.ts
+++ b/lib/jmap/client.ts
@@ -548,6 +548,53 @@ export class JMAPClient {
     }
   }
 
+  async getTagCounts(tagIds: string[]): Promise<Record<string, { total: number; unread: number }>> {
+    if (tagIds.length === 0) return {};
+    try {
+      const methodCalls: JMAPMethodCall[] = [];
+      for (let i = 0; i < tagIds.length; i++) {
+        const keyword = `$label:${tagIds[i]}`;
+        // Total count for this tag
+        methodCalls.push(["Email/query", {
+          accountId: this.accountId,
+          filter: { hasKeyword: keyword },
+          limit: 0,
+          calculateTotal: true,
+        }, `total_${i}`]);
+        // Unread count for this tag
+        methodCalls.push(["Email/query", {
+          accountId: this.accountId,
+          filter: {
+            operator: "AND",
+            conditions: [
+              { hasKeyword: keyword },
+              { notKeyword: "$seen" },
+            ],
+          },
+          limit: 0,
+          calculateTotal: true,
+        }, `unread_${i}`]);
+      }
+
+      const response = await this.request(methodCalls);
+      const result: Record<string, { total: number; unread: number }> = {};
+
+      for (let i = 0; i < tagIds.length; i++) {
+        const totalResp = response.methodResponses?.[i * 2]?.[1];
+        const unreadResp = response.methodResponses?.[i * 2 + 1]?.[1];
+        result[tagIds[i]] = {
+          total: totalResp?.total ?? 0,
+          unread: unreadResp?.total ?? 0,
+        };
+      }
+
+      return result;
+    } catch (error) {
+      console.error('Failed to get tag counts:', error);
+      return {};
+    }
+  }
+
   async getEmail(emailId: string, accountId?: string): Promise<Email | null> {
     try {
       const targetAccountId = accountId || this.accountId;
diff --git a/stores/email-store.ts b/stores/email-store.ts
index 5fd2eafe..a6c198da 100644
--- a/stores/email-store.ts
+++ b/stores/email-store.ts
@@ -31,6 +31,7 @@ interface EmailStore {
 
   // Keyword/tag filter
   selectedKeyword: string | null;
+  tagCounts: Record<string, { total: number; unread: number }>;
 
   // Advanced search state
   searchFilters: SearchFilters;
@@ -47,6 +48,7 @@ interface EmailStore {
   setSearchQuery: (query: string) => void;
   setQuota: (quota: { used: number; total: number } | null) => void;
   selectKeyword: (keyword: string | null) => void;
+  fetchTagCounts: (client: JMAPClient) => Promise<void>;
   toggleEmailSelection: (emailId: string) => void;
   selectRangeEmails: (targetEmailId: string) => void;
   lastSelectedEmailId: string | null;
@@ -143,6 +145,7 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
 
   // Keyword/tag filter
   selectedKeyword: null,
+  tagCounts: {},
 
   // Advanced search state
   searchFilters: { ...DEFAULT_SEARCH_FILTERS },
@@ -162,6 +165,20 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
     expandedThreadIds: new Set(),
     threadEmailsCache: new Map(),
   }),
+  fetchTagCounts: async (client) => {
+    try {
+      const keywords = useSettingsStore.getState().emailKeywords;
+      if (keywords.length === 0) {
+        set({ tagCounts: {} });
+        return;
+      }
+      const tagIds = keywords.map(k => k.id);
+      const counts = await client.getTagCounts(tagIds);
+      set({ tagCounts: counts });
+    } catch (error) {
+      console.error('Failed to fetch tag counts:', error);
+    }
+  },
   selectMailbox: (mailboxId) => set({
     selectedMailbox: mailboxId,
     selectedEmail: null,
@@ -1040,6 +1057,7 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
       // Handle Email state changes - refresh current mailbox
       if (accountChanges.Email) {
         await get().refreshCurrentMailbox(client);
+        get().fetchTagCounts(client);
       }
 
       // Handle Mailbox state changes - refresh mailbox list