diff --git a/src/App.svelte b/src/App.svelte
index 6b8435e..37a2923 100644
--- a/src/App.svelte
+++ b/src/App.svelte
@@ -23,8 +23,8 @@
     savePitchLockFrequency,
     loadExpandedCategories,
     saveExpandedCategories,
-    loadEnabledProcessorCategories,
-    saveEnabledProcessorCategories,
+    loadSelectedProcessorCategory,
+    saveSelectedProcessorCategory,
   } from "./lib/utils/settings";
   import {
     cropAudio,
@@ -68,8 +68,8 @@
   let canUndo = $state(false);
   let sidebarOpen = $state(false);
   let expandedCategories = $state<Set<string>>(loadExpandedCategories());
-  let enabledProcessorCategories = $state<Set<ProcessorCategory>>(
-    loadEnabledProcessorCategories() as Set<ProcessorCategory>
+  let selectedProcessorCategory = $state<ProcessorCategory | 'All'>(
+    loadSelectedProcessorCategory()
   );
 
   const showDuration = $derived(engineType !== "sample");
@@ -111,7 +111,7 @@
   });
 
   $effect(() => {
-    saveEnabledProcessorCategories(enabledProcessorCategories as Set<string>);
+    saveSelectedProcessorCategory(selectedProcessorCategory);
   });
 
   // Group engines by category
@@ -137,14 +137,8 @@
     expandedCategories = newSet;
   }
 
-  function toggleProcessorCategory(category: ProcessorCategory) {
-    const newSet = new Set(enabledProcessorCategories);
-    if (newSet.has(category)) {
-      newSet.delete(category);
-    } else {
-      newSet.add(category);
-    }
-    enabledProcessorCategories = newSet;
+  function selectProcessorCategory(category: ProcessorCategory | 'All') {
+    selectedProcessorCategory = category;
   }
 
   onMount(() => {
@@ -714,8 +708,8 @@
                 <div onmouseenter={keepPopupOpen} onmouseleave={scheduleHidePopup}>
                   <ProcessorPopup
                     onselect={applyProcessor}
-                    enabledCategories={enabledProcessorCategories}
-                    ontogglecategory={toggleProcessorCategory}
+                    selectedCategory={selectedProcessorCategory}
+                    onselectcategory={selectProcessorCategory}
                   />
                 </div>
               {/if}
diff --git a/src/lib/components/ProcessorPopup.svelte b/src/lib/components/ProcessorPopup.svelte
index 6997822..a0a1064 100644
--- a/src/lib/components/ProcessorPopup.svelte
+++ b/src/lib/components/ProcessorPopup.svelte
@@ -4,11 +4,11 @@
 
   interface Props {
     onselect: (processor: AudioProcessor) => void;
-    enabledCategories: Set<ProcessorCategory>;
-    ontogglecategory: (category: ProcessorCategory) => void;
+    selectedCategory: ProcessorCategory | 'All';
+    onselectcategory: (category: ProcessorCategory | 'All') => void;
   }
 
-  let { onselect, enabledCategories, ontogglecategory }: Props = $props();
+  let { onselect, selectedCategory, onselectcategory }: Props = $props();
 
   const allProcessors = getAllProcessors();
 
@@ -24,22 +24,40 @@
     'Utility'
   ];
 
+  const categoryCountsMap = $derived.by(() => {
+    const counts = new Map<ProcessorCategory, number>();
+    for (const processor of allProcessors) {
+      const category = processor.getCategory();
+      counts.set(category, (counts.get(category) || 0) + 1);
+    }
+    return counts;
+  });
+
   const filteredProcessors = $derived(
-    allProcessors
-      .filter(p => enabledCategories.has(p.getCategory()))
-      .sort((a, b) => a.getName().localeCompare(b.getName()))
+    selectedCategory === 'All'
+      ? allProcessors.sort((a, b) => a.getName().localeCompare(b.getName()))
+      : allProcessors
+          .filter(p => p.getCategory() === selectedCategory)
+          .sort((a, b) => a.getName().localeCompare(b.getName()))
   );
 </script>
 
 <div class="processor-popup">
   <div class="popup-sidebar">
+    <button
+      class="category-filter"
+      class:active={selectedCategory === 'All'}
+      onclick={() => onselectcategory('All')}
+    >
+      All ({allProcessors.length})
+    </button>
     {#each allCategories as category}
       <button
         class="category-filter"
-        class:active={enabledCategories.has(category)}
-        onclick={() => ontogglecategory(category)}
+        class:active={selectedCategory === category}
+        onclick={() => onselectcategory(category)}
       >
-        {category}
+        {category} ({categoryCountsMap.get(category) || 0})
       </button>
     {/each}
   </div>
diff --git a/src/lib/utils/settings.ts b/src/lib/utils/settings.ts
index 9d06b4d..f8a7881 100644
--- a/src/lib/utils/settings.ts
+++ b/src/lib/utils/settings.ts
@@ -9,7 +9,7 @@ const STORAGE_KEYS = {
   PITCH_LOCK_ENABLED: 'pitchLockEnabled',
   PITCH_LOCK_FREQUENCY: 'pitchLockFrequency',
   EXPANDED_CATEGORIES: 'expandedCategories',
-  ENABLED_PROCESSOR_CATEGORIES: 'enabledProcessorCategories',
+  SELECTED_PROCESSOR_CATEGORY: 'selectedProcessorCategory',
 } as const;
 
 export function loadVolume(): number {
@@ -65,19 +65,11 @@ export function saveExpandedCategories(categories: Set<string>): void {
   localStorage.setItem(STORAGE_KEYS.EXPANDED_CATEGORIES, JSON.stringify(Array.from(categories)));
 }
 
-export function loadEnabledProcessorCategories(): Set<string> {
-  const stored = localStorage.getItem(STORAGE_KEYS.ENABLED_PROCESSOR_CATEGORIES);
-  if (stored) {
-    try {
-      const parsed = JSON.parse(stored);
-      return new Set(Array.isArray(parsed) ? parsed : []);
-    } catch {
-      return new Set(['Amplitude', 'Filter', 'Time', 'Space', 'Pitch', 'Modulation', 'Distortion', 'Spectral', 'Utility']);
-    }
-  }
-  return new Set(['Amplitude', 'Filter', 'Time', 'Space', 'Pitch', 'Modulation', 'Distortion', 'Spectral', 'Utility']);
+export function loadSelectedProcessorCategory(): string {
+  const stored = localStorage.getItem(STORAGE_KEYS.SELECTED_PROCESSOR_CATEGORY);
+  return stored || 'All';
 }
 
-export function saveEnabledProcessorCategories(categories: Set<string>): void {
-  localStorage.setItem(STORAGE_KEYS.ENABLED_PROCESSOR_CATEGORIES, JSON.stringify(Array.from(categories)));
+export function saveSelectedProcessorCategory(category: string): void {
+  localStorage.setItem(STORAGE_KEYS.SELECTED_PROCESSOR_CATEGORY, category);
 }