diff --git a/api_server.py b/api_server.py
index 1a5e1a8..9272436 100644
--- a/api_server.py
+++ b/api_server.py
@@ -361,13 +361,63 @@ async def get_integrations():
 
 @app.get("/api/categories")
 async def get_categories():
-    """Get available service categories for filtering."""
+    """Get available workflow categories for filtering."""
     try:
-        categories = db.get_service_categories()
-        return {"categories": categories}
+        # Try to load from the generated unique categories file
+        categories_file = Path("context/unique_categories.json")
+        if categories_file.exists():
+            with open(categories_file, 'r', encoding='utf-8') as f:
+                categories = json.load(f)
+            return {"categories": categories}
+        else:
+            # Fallback: extract categories from search_categories.json
+            search_categories_file = Path("context/search_categories.json")
+            if search_categories_file.exists():
+                with open(search_categories_file, 'r', encoding='utf-8') as f:
+                    search_data = json.load(f)
+                
+                unique_categories = set()
+                for item in search_data:
+                    if item.get('category'):
+                        unique_categories.add(item['category'])
+                    else:
+                        unique_categories.add('Uncategorized')
+                
+                categories = sorted(list(unique_categories))
+                return {"categories": categories}
+            else:
+                # Last resort: return basic categories
+                return {"categories": ["Uncategorized"]}
+                
     except Exception as e:
+        print(f"Error loading categories: {e}")
         raise HTTPException(status_code=500, detail=f"Error fetching categories: {str(e)}")
 
+@app.get("/api/category-mappings")
+async def get_category_mappings():
+    """Get filename to category mappings for client-side filtering."""
+    try:
+        search_categories_file = Path("context/search_categories.json")
+        if not search_categories_file.exists():
+            return {"mappings": {}}
+        
+        with open(search_categories_file, 'r', encoding='utf-8') as f:
+            search_data = json.load(f)
+        
+        # Convert to a simple filename -> category mapping
+        mappings = {}
+        for item in search_data:
+            filename = item.get('filename')
+            category = item.get('category') or 'Uncategorized'
+            if filename:
+                mappings[filename] = category
+        
+        return {"mappings": mappings}
+        
+    except Exception as e:
+        print(f"Error loading category mappings: {e}")
+        raise HTTPException(status_code=500, detail=f"Error fetching category mappings: {str(e)}")
+
 @app.get("/api/workflows/category/{category}", response_model=SearchResponse)
 async def search_workflows_by_category(
     category: str,
diff --git a/create_categories.py b/create_categories.py
index c534fa7..374b6a4 100644
--- a/create_categories.py
+++ b/create_categories.py
@@ -75,6 +75,25 @@ def main():
     
     print(f"Generated search_categories.json with {len(search_categories)} entries")
     
+    # Generate unique categories list for API
+    unique_categories = set()
+    for item in search_categories:
+        if item['category']:
+            unique_categories.add(item['category'])
+    
+    # Always include 'Uncategorized' for workflows without categories
+    unique_categories.add('Uncategorized')
+    
+    # Sort categories alphabetically
+    categories_list = sorted(list(unique_categories))
+    
+    # Write unique categories to a separate file for API consumption
+    categories_output_path = Path("context/unique_categories.json")
+    with open(categories_output_path, 'w', encoding='utf-8') as f:
+        json.dump(categories_list, f, indent=2, ensure_ascii=False)
+    
+    print(f"Generated unique_categories.json with {len(categories_list)} categories")
+    
     # Print some statistics
     categorized = sum(1 for item in search_categories if item['category'])
     uncategorized = len(search_categories) - categorized
diff --git a/static/index.html b/static/index.html
index 967b8f3..132991e 100644
--- a/static/index.html
+++ b/static/index.html
@@ -302,6 +302,16 @@
       font-weight: 500;
     }
 
+    .category-badge {
+      background: var(--bg-tertiary);
+      color: var(--text-secondary);
+      padding: 0.125rem 0.375rem;
+      border-radius: 0.25rem;
+      font-size: 0.75rem;
+      border: 1px solid var(--border);
+      font-weight: 500;
+    }
+
     .workflow-title {
       font-size: 1.25rem;
       font-weight: 600;
@@ -623,6 +633,14 @@
             </select>
           </div>
 
+          <div class="filter-group">
+            <label for="categoryFilter">Category:</label>
+            <select id="categoryFilter">
+              <option value="all">All Categories</option>
+              <!-- Categories will be populated dynamically -->
+            </select>
+          </div>
+
           <div class="filter-group">
             <label>
               <input type="checkbox" id="activeOnly">
@@ -747,14 +765,18 @@
           filters: {
             trigger: 'all',
             complexity: 'all',
+            category: 'all',
             activeOnly: false
-          }
+          },
+          categories: [],
+          categoryMap: new Map()
         };
 
         this.elements = {
           searchInput: document.getElementById('searchInput'),
           triggerFilter: document.getElementById('triggerFilter'),
           complexityFilter: document.getElementById('complexityFilter'),
+          categoryFilter: document.getElementById('categoryFilter'),
           activeOnlyFilter: document.getElementById('activeOnly'),
           themeToggle: document.getElementById('themeToggle'),
           resultsCount: document.getElementById('resultsCount'),
@@ -839,6 +861,16 @@
           this.resetAndSearch();
         });
 
+        this.elements.categoryFilter.addEventListener('change', (e) => {
+          const selectedCategory = e.target.value;
+          console.log(`Category filter changed to: ${selectedCategory}`);
+          console.log('Current category map size:', this.state.categoryMap.size);
+          
+          this.state.filters.category = selectedCategory;
+          this.state.currentPage = 1;
+          this.resetAndSearch();
+        });
+
         this.elements.activeOnlyFilter.addEventListener('change', (e) => {
           this.state.filters.activeOnly = e.target.checked;
           this.state.currentPage = 1;
@@ -942,18 +974,96 @@
         this.showState('loading');
 
         try {
+          // Load categories first, then stats and workflows
+          console.log('Loading categories...');
+          await this.loadCategories();
+          
+          console.log('Categories loaded, populating filter...');
+          this.populateCategoryFilter();
+          
           // Load stats and workflows in parallel
-          const [stats, workflows] = await Promise.all([
+          console.log('Loading stats and workflows...');
+          const [stats] = await Promise.all([
             this.apiCall('/stats'),
             this.loadWorkflows(true)
           ]);
 
           this.updateStatsDisplay(stats);
+          console.log('Initial data loading complete');
         } catch (error) {
+          console.error('Error during initial data loading:', error);
           this.showError('Failed to load data: ' + error.message);
         }
       }
 
+      async loadCategories() {
+        try {
+          console.log('Loading categories from API...');
+          
+          // Load categories and mappings in parallel from API
+          const [categoriesResponse, mappingsResponse] = await Promise.all([
+            this.apiCall('/categories'),
+            this.apiCall('/category-mappings')
+          ]);
+          
+          // Set categories from API
+          this.state.categories = categoriesResponse.categories || ['Uncategorized'];
+          
+          // Build category map from API mappings
+          const categoryMap = new Map();
+          const mappings = mappingsResponse.mappings || {};
+          
+          Object.entries(mappings).forEach(([filename, category]) => {
+            categoryMap.set(filename, category || 'Uncategorized');
+          });
+          
+          this.state.categoryMap = categoryMap;
+          
+          console.log(`Successfully loaded ${this.state.categories.length} categories from API:`, this.state.categories);
+          console.log(`Loaded ${categoryMap.size} category mappings from API`);
+          
+          return { categories: this.state.categories, mappings: mappings };
+        } catch (error) {
+          console.error('Failed to load categories from API:', error);
+          // Set default categories if loading fails
+          this.state.categories = ['Uncategorized'];
+          this.state.categoryMap = new Map();
+          return { categories: this.state.categories, mappings: {} };
+        }
+      }
+
+      populateCategoryFilter() {
+        const select = this.elements.categoryFilter;
+        
+        if (!select) {
+          console.error('Category filter element not found');
+          return;
+        }
+        
+        console.log('Populating category filter with:', this.state.categories);
+        
+        // Clear existing options except "All Categories"
+        while (select.children.length > 1) {
+          select.removeChild(select.lastChild);
+        }
+        
+        if (this.state.categories.length === 0) {
+          console.warn('No categories available to populate filter');
+          return;
+        }
+        
+        // Add categories in alphabetical order
+        this.state.categories.forEach(category => {
+          const option = document.createElement('option');
+          option.value = category;
+          option.textContent = category;
+          select.appendChild(option);
+          console.log(`Added category option: ${category}`);
+        });
+        
+        console.log(`Category filter populated with ${select.options.length - 1} categories`);
+      }
+
       async loadWorkflows(reset = false) {
         if (reset) {
           this.state.currentPage = 1;
@@ -963,25 +1073,65 @@
         this.state.isLoading = true;
 
         try {
-          const params = new URLSearchParams({
-            q: this.state.searchQuery,
-            trigger: this.state.filters.trigger,
-            complexity: this.state.filters.complexity,
-            active_only: this.state.filters.activeOnly,
-            page: this.state.currentPage,
-            per_page: this.state.perPage
-          });
-
-          const response = await this.apiCall(`/workflows?${params}`);
-
-          if (reset) {
-            this.state.workflows = response.workflows;
+          // If category filtering is active, we need to load all workflows to filter properly
+          const needsAllWorkflows = this.state.filters.category !== 'all' && reset;
+          
+          let allWorkflows = [];
+          let totalCount = 0;
+          let totalPages = 1;
+          
+          if (needsAllWorkflows) {
+            // Load all workflows in batches for category filtering
+            console.log('Loading all workflows for category filtering...');
+            allWorkflows = await this.loadAllWorkflowsForCategoryFiltering();
+            
+            // Apply client-side category filtering
+            console.log(`Filtering ${allWorkflows.length} workflows for category: ${this.state.filters.category}`);
+            console.log('Category map size:', this.state.categoryMap.size);
+            
+            let matchCount = 0;
+            const filteredWorkflows = allWorkflows.filter(workflow => {
+              const workflowCategory = this.getWorkflowCategory(workflow.filename);
+              const matches = workflowCategory === this.state.filters.category;
+              
+              // Debug: log first few matches/non-matches
+              if (matchCount < 5 || (!matches && matchCount < 3)) {
+                console.log(`${workflow.filename}: ${workflowCategory} ${matches ? '===' : '!=='} ${this.state.filters.category}`);
+              }
+              
+              if (matches) matchCount++;
+              
+              return matches;
+            });
+            
+            console.log(`Filtered from ${allWorkflows.length} to ${filteredWorkflows.length} workflows`);
+            allWorkflows = filteredWorkflows;
+            totalCount = filteredWorkflows.length;
+            totalPages = 1; // All results loaded, no pagination needed
           } else {
-            this.state.workflows.push(...response.workflows);
+            // Normal pagination
+            const params = new URLSearchParams({
+              q: this.state.searchQuery,
+              trigger: this.state.filters.trigger,
+              complexity: this.state.filters.complexity,
+              active_only: this.state.filters.activeOnly,
+              page: this.state.currentPage,
+              per_page: this.state.perPage
+            });
+
+            const response = await this.apiCall(`/workflows?${params}`);
+            allWorkflows = response.workflows;
+            totalCount = response.total;
+            totalPages = response.pages;
           }
 
-          this.state.totalCount = response.total;
-          this.state.totalPages = response.pages;
+          if (reset) {
+            this.state.workflows = allWorkflows;
+            this.state.totalCount = totalCount;
+            this.state.totalPages = totalPages;
+          } else {
+            this.state.workflows.push(...allWorkflows);
+          }
 
           this.updateUI();
 
@@ -992,6 +1142,43 @@
         }
       }
 
+      async loadAllWorkflowsForCategoryFiltering() {
+        const allWorkflows = [];
+        let currentPage = 1;
+        const maxPerPage = 100; // API limit
+        
+        while (true) {
+          const params = new URLSearchParams({
+            q: this.state.searchQuery,
+            trigger: this.state.filters.trigger,
+            complexity: this.state.filters.complexity,
+            active_only: this.state.filters.activeOnly,
+            page: currentPage,
+            per_page: maxPerPage
+          });
+
+          const response = await this.apiCall(`/workflows?${params}`);
+          allWorkflows.push(...response.workflows);
+          
+          console.log(`Loaded page ${currentPage}/${response.pages} (${response.workflows.length} workflows)`);
+          
+          if (currentPage >= response.pages) {
+            break;
+          }
+          
+          currentPage++;
+        }
+        
+        console.log(`Loaded total of ${allWorkflows.length} workflows for filtering`);
+        return allWorkflows;
+      }
+
+      getWorkflowCategory(filename) {
+        const category = this.state.categoryMap.get(filename);
+        const result = category && category.trim() ? category : 'Uncategorized';
+        return result;
+      }
+
       async loadMoreWorkflows() {
         if (this.state.currentPage >= this.state.totalPages) return;
 
@@ -1025,12 +1212,19 @@
       updateResultsCount() {
         const count = this.state.totalCount;
         const query = this.state.searchQuery;
-
-        if (query) {
-          this.elements.resultsCount.textContent = `${count.toLocaleString()} workflows found for "${query}"`;
-        } else {
-          this.elements.resultsCount.textContent = `${count.toLocaleString()} workflows`;
+        const category = this.state.filters.category;
+        
+        let text = `${count.toLocaleString()} workflows`;
+        
+        if (query && category !== 'all') {
+          text += ` found for "${query}" in "${category}"`;
+        } else if (query) {
+          text += ` found for "${query}"`;
+        } else if (category !== 'all') {
+          text += ` in "${category}"`;
         }
+        
+        this.elements.resultsCount.textContent = text;
       }
 
       renderWorkflows() {
@@ -1048,6 +1242,7 @@
       createWorkflowCard(workflow) {
         const statusClass = workflow.active ? 'status-active' : 'status-inactive';
         const complexityClass = `complexity-${workflow.complexity}`;
+        const category = this.getWorkflowCategory(workflow.filename);
 
         const integrations = workflow.integrations.slice(0, 5).map(integration =>
           `<span class="integration-tag">${this.escapeHtml(integration)}</span>`
@@ -1064,6 +1259,7 @@
                                 <div class="status-dot ${statusClass}"></div>
                                 <div class="complexity-dot ${complexityClass}"></div>
                                 <span>${workflow.node_count} nodes</span>
+                                <span class="category-badge">${this.escapeHtml(category)}</span>
                             </div>
                             <span class="trigger-badge">${this.escapeHtml(workflow.trigger_type)}</span>
                         </div>
@@ -1090,12 +1286,14 @@
         this.elements.modalDescription.textContent = workflow.description;
 
         // Update stats
+        const category = this.getWorkflowCategory(workflow.filename);
         this.elements.modalStats.innerHTML = `
                     <div style="display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1rem;">
                         <div><strong>Status:</strong> ${workflow.active ? 'Active' : 'Inactive'}</div>
                         <div><strong>Trigger:</strong> ${workflow.trigger_type}</div>
                         <div><strong>Complexity:</strong> ${workflow.complexity}</div>
                         <div><strong>Nodes:</strong> ${workflow.node_count}</div>
+                        <div><strong>Category:</strong> ${this.escapeHtml(category)}</div>
                     </div>
                 `;