diff --git a/FEATURES.md b/FEATURES.md
index 3f04221b..2ae105f0 100644
--- a/FEATURES.md
+++ b/FEATURES.md
@@ -18,6 +18,7 @@
 - Archive directly, by year, or by month
 - Tags carry color labels, reorder by drag, and can be assigned by dropping a message onto them
 - Tags optionally nest: pick a parent when you create one and the sidebar turns them into a tree
+- Each tag can be configured to show always, only when there are unread mails or always be hidden
 - Star or unstar, with a configurable mark-as-read delay
 - Large mailboxes scroll virtually, and the first page of mail prefetches at login
 - Quick reply, hover actions, favicon-based sender avatars, recipient popovers
diff --git a/components/layout/sidebar.tsx b/components/layout/sidebar.tsx
index 06a9b662..31070e1d 100644
--- a/components/layout/sidebar.tsx
+++ b/components/layout/sidebar.tsx
@@ -35,10 +35,17 @@ import {
   BellOff,
   Mails,
   MailOpen,
+  MoreHorizontal,
 } from "lucide-react";
 import { cn, buildMailboxTree, MailboxNode } from "@/lib/utils";
 import { localizeMailboxName } from "@/lib/mailbox-label";
-import { buildKeywordTree, hasChildKeywords, type KeywordNode } from "@/lib/keyword-nesting";
+import {
+  buildKeywordTree,
+  countKeywordNodes,
+  filterKeywordTree,
+  hasChildKeywords,
+  type KeywordNode,
+} from "@/lib/keyword-nesting";
 import { useShortenedText } from "@/hooks/use-shortened-text";
 import { useKeywordFormat } from "@/hooks/use-keyword-format";
 import { isEditableEventTarget } from "@/lib/keyboard";
@@ -54,7 +61,7 @@ import { useTagDrop } from "@/hooks/use-tag-drop";
 import { useUIStore } from "@/stores/ui-store";
 import { useAuthStore } from "@/stores/auth-store";
 import { useVacationStore } from "@/stores/vacation-store";
-import { useSettingsStore, KEYWORD_PALETTE } from "@/stores/settings-store";
+import { useSettingsStore, KEYWORD_PALETTE, getKeywordVisibility } from "@/stores/settings-store";
 import { useEmailStore } from "@/stores/email-store";
 import { toast } from "@/stores/toast-store";
 import { debug } from "@/lib/debug";
@@ -566,6 +573,30 @@ const TAG_ICON_COLOR: Record<string, string> = {
   gray: "text-gray-500",
 };
 
+function ShowAllTagsRow({
+  hiddenCount,
+  showAll,
+  onToggle,
+  isCollapsed,
+}: {
+  hiddenCount: number;
+  showAll: boolean;
+  onToggle: () => void;
+  isCollapsed: boolean;
+}) {
+  const t = useTranslations('sidebar');
+
+  return (
+    <SidebarRow
+      icon={<MoreHorizontal className="w-4 h-4 text-muted-foreground" />}
+      label={showAll ? t('show_fewer_tags') : t('show_all_tags', { count: hiddenCount })}
+      depth={0}
+      onClick={onToggle}
+      isCollapsed={isCollapsed}
+    />
+  );
+}
+
 function TagItem({
   node,
   selectedKeyword,
@@ -778,6 +809,7 @@ export function Sidebar({
   const { primaryIdentity: _primaryIdentity, activeAccountId } = useAuthStore();
   const [expandedFolders, setExpandedFolders] = useState<Set<string>>(new Set());
   const [expandedTags, setExpandedTags] = useState<Set<string>>(new Set());
+  const [showAllTags, setShowAllTags] = useState(false);
   const [foldersExpanded, setFoldersExpanded] = useState(() => {
     try {
       const stored = localStorage.getItem('sidebarFoldersExpanded');
@@ -931,6 +963,19 @@ export function Sidebar({
     ? buildKeywordTree(emailKeywords)
     : emailKeywords.map((kw) => ({ ...kw, children: [], depth: 0 }));
 
+  // Counts arrive from a separate JMAP round trip; until they land, treat every
+  // "show if unread" tag as visible rather than blanking the section and
+  // filling it back in.
+  const tagCountsLoaded = Object.keys(tagCounts).length > 0;
+  const isTagVisible = (node: KeywordNode) => {
+    if (showAllTags || node.id === selectedKeyword) return true;
+    const visibility = getKeywordVisibility(node);
+    if (visibility === 'hide') return false;
+    if (visibility === 'unread') return !tagCountsLoaded || (tagCounts[node.id]?.unread ?? 0) > 0;
+    return true;
+  };
+  const visibleTagTree = filterKeywordTree(tagTree, isTagVisible);
+  const hiddenTagCount = emailKeywords.length - countKeywordNodes(visibleTagTree);
 
   // Multi-account mode (Pro shell): render every connected account as its
   // own collapsible group. The active account's tree comes from the
@@ -1345,7 +1390,7 @@ export function Sidebar({
             />
             {((tagsExpanded && !isCollapsed) || isCollapsed) && (
               <>
-                {tagTree.map((node) => (
+                {visibleTagTree.map((node) => (
                   <TagItem
                     key={node.id}
                     node={node}
@@ -1358,6 +1403,14 @@ export function Sidebar({
                     colorful={colorfulSidebarIcons}
                   />
                 ))}
+                {(hiddenTagCount > 0 || showAllTags) && (
+                  <ShowAllTagsRow
+                    hiddenCount={hiddenTagCount}
+                    showAll={showAllTags}
+                    onToggle={() => setShowAllTags((prev) => !prev)}
+                    isCollapsed={isCollapsed}
+                  />
+                )}
               </>
             )}
           </div>
diff --git a/components/settings/__tests__/keyword-settings.test.tsx b/components/settings/__tests__/keyword-settings.test.tsx
index 8593c41f..eb3119f3 100644
--- a/components/settings/__tests__/keyword-settings.test.tsx
+++ b/components/settings/__tests__/keyword-settings.test.tsx
@@ -210,4 +210,20 @@ describe('KeywordSettings', () => {
     expect(screen.getByDisplayValue('Work')).toBeDisabled();
     expect(screen.getByText('has_children_locked')).toBeInTheDocument();
   });
+
+  it('defaults every tag to always visible in the sidebar', () => {
+    render(<KeywordSettings />);
+
+    const pickers = screen.getAllByLabelText('visibility_field');
+    expect(pickers).toHaveLength(DEFAULT_KEYWORDS.length);
+    pickers.forEach((picker) => expect(picker).toHaveValue('show'));
+  });
+
+  it('stores the visibility chosen for a tag', () => {
+    render(<KeywordSettings />);
+
+    fireEvent.change(screen.getAllByLabelText('visibility_field')[0], { target: { value: 'unread' } });
+
+    expect(useSettingsStore.getState().emailKeywords.find((k) => k.id === 'red')?.visibility).toBe('unread');
+  });
 });
diff --git a/components/settings/keyword-settings.tsx b/components/settings/keyword-settings.tsx
index cd6f408f..9689ab08 100644
--- a/components/settings/keyword-settings.tsx
+++ b/components/settings/keyword-settings.tsx
@@ -6,7 +6,9 @@ import {
   useSettingsStore,
   KEYWORD_PALETTE,
   DEFAULT_KEYWORDS,
+  getKeywordVisibility,
   type KeywordDefinition,
+  type KeywordVisibility,
 } from "@/stores/settings-store";
 import { useAuthStore } from "@/stores/auth-store";
 import { useEmailStore } from "@/stores/email-store";
@@ -61,6 +63,7 @@ function KeywordRow({
   nestedTags,
   onEdit,
   onDelete,
+  onVisibilityChange,
   onDragStart,
   onDragOver,
   onDrop,
@@ -73,6 +76,7 @@ function KeywordRow({
   nestedTags: boolean;
   onEdit: () => void;
   onDelete: () => void;
+  onVisibilityChange: (visibility: KeywordVisibility) => void;
   onDragStart: () => void;
   onDragOver: (e: React.DragEvent) => void;
   onDrop: () => void;
@@ -89,6 +93,11 @@ function KeywordRow({
   const keywordCandidates = (nestedTags ? keywordRenderings(keywordLevels(keyword.id)) : [keyword.id])
     .map((rendering) => KEYWORD_PREFIX + rendering);
   const [keywordRef, shortenedKeyword] = useShortenedText(keywordCandidates);
+  const visibilityOptions = [
+    { value: "show", label: t("visibility.show") },
+    { value: "unread", label: t("visibility.unread") },
+    { value: "hide", label: t("visibility.hide") },
+  ];
 
   return (
     <div
@@ -119,6 +128,13 @@ function KeywordRow({
       >
         {shortenedKeyword}
       </span>
+      <Select
+        value={getKeywordVisibility(keyword)}
+        onChange={(value) => onVisibilityChange(value as KeywordVisibility)}
+        options={visibilityOptions}
+        ariaLabel={t("visibility_field")}
+        className="text-xs py-1"
+      />
       <div className="flex items-center gap-1 opacity-0 group-hover:opacity-100 transition-opacity">
         <button
           type="button"
@@ -353,6 +369,10 @@ export function KeywordSettings() {
     removeKeyword(id);
   };
 
+  const handleVisibilityChange = (id: string, visibility: KeywordVisibility) => {
+    updateKeyword(id, { visibility });
+  };
+
   const handleResetDefaults = () => {
     reorderKeywords(DEFAULT_KEYWORDS);
   };
@@ -395,6 +415,7 @@ export function KeywordSettings() {
                 setIsAdding(false);
               }}
               onDelete={() => handleDelete(keyword.id)}
+              onVisibilityChange={(visibility) => handleVisibilityChange(keyword.id, visibility)}
               onDragStart={() => handleDragStart(index)}
               onDragOver={(e) => handleDragOver(e, index)}
               onDrop={() => handleDrop(index)}
diff --git a/lib/__tests__/keyword-nesting.test.ts b/lib/__tests__/keyword-nesting.test.ts
index 709b6c38..888c45ad 100644
--- a/lib/__tests__/keyword-nesting.test.ts
+++ b/lib/__tests__/keyword-nesting.test.ts
@@ -3,6 +3,8 @@ import {
   MAX_KEYWORD_ID_LENGTH,
   buildKeywordTree,
   composeKeywordId,
+  countKeywordNodes,
+  filterKeywordTree,
   getParentKeywordId,
   hasChildKeywords,
   isKeywordDescendant,
@@ -136,3 +138,46 @@ describe("buildKeywordTree", () => {
     expect(flat.every((n) => n.depth === 0 && n.children.length === 0)).toBe(true);
   });
 });
+
+describe("filterKeywordTree", () => {
+  const tree = buildKeywordTree(KEYWORDS);
+
+  it("drops the nodes the predicate rejects", () => {
+    const kept = filterKeywordTree(tree, (node) => node.id !== "work/personal");
+    const [work] = kept;
+
+    expect(work.children.map((c) => c.id)).toEqual(["work/clients"]);
+  });
+
+  it("keeps a rejected node when a descendant survives, so nothing is stranded", () => {
+    const kept = filterKeywordTree(tree, (node) => node.id === "work/clients/acme");
+    const [work] = kept;
+
+    expect(work.id).toBe("work");
+    expect(work.children.map((c) => c.id)).toEqual(["work/clients"]);
+    expect(work.children[0].children.map((c) => c.id)).toEqual(["work/clients/acme"]);
+  });
+
+  it("keeps the depth of a surviving node so its indentation does not shift", () => {
+    const kept = filterKeywordTree(tree, (node) => node.id === "work/clients/acme");
+
+    expect(kept[0].children[0].children[0].depth).toBe(2);
+  });
+
+  it("returns nothing when the predicate rejects everything", () => {
+    expect(filterKeywordTree(tree, () => false)).toEqual([]);
+  });
+
+  it("leaves the original tree untouched", () => {
+    filterKeywordTree(tree, (node) => node.id === "work");
+
+    expect(countKeywordNodes(tree)).toBe(4);
+  });
+});
+
+describe("countKeywordNodes", () => {
+  it("counts every level, not just the roots", () => {
+    expect(countKeywordNodes(buildKeywordTree(KEYWORDS))).toBe(4);
+    expect(countKeywordNodes([])).toBe(0);
+  });
+});
diff --git a/lib/keyword-nesting.ts b/lib/keyword-nesting.ts
index b2d77e72..57a4fc9b 100644
--- a/lib/keyword-nesting.ts
+++ b/lib/keyword-nesting.ts
@@ -111,3 +111,29 @@ export function buildKeywordTree(keywords: KeywordDefinition[]): KeywordNode[] {
   return roots;
 }
 
+/**
+ * Prunes a tag tree down to the nodes worth showing.
+ *
+ * A node survives when the predicate accepts it or when any of its descendants
+ * survives, so hiding a parent never strands the children below it. Depths are
+ * left untouched: a kept node keeps the indentation of its original level even
+ * when the level above it is only there to carry it.
+ */
+export function filterKeywordTree(
+  nodes: KeywordNode[],
+  isVisible: (node: KeywordNode) => boolean,
+): KeywordNode[] {
+  const kept: KeywordNode[] = [];
+  for (const node of nodes) {
+    const children = filterKeywordTree(node.children, isVisible);
+    if (children.length > 0 || isVisible(node)) {
+      kept.push({ ...node, children });
+    }
+  }
+  return kept;
+}
+
+/** Total number of nodes in a tag tree, at every level. */
+export function countKeywordNodes(nodes: KeywordNode[]): number {
+  return nodes.reduce((total, node) => total + 1 + countKeywordNodes(node.children), 0);
+}
diff --git a/locales/en/common.json b/locales/en/common.json
index 96526730..c2595689 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -130,6 +130,8 @@
     "demo_reset": "Reset",
     "demo_tour": "Tour",
     "tags": "Tags",
+    "show_all_tags": "Show all ({count})",
+    "show_fewer_tags": "Show less",
     "folders": "Folders",
     "shared": "Shared",
     "mail": "Mail",
@@ -1041,7 +1043,13 @@
       "no_parent": "No parent",
       "too_long": "This tag path is too long (at most {max} characters)",
       "has_children_locked": "Other tags are nested under this one, so its name and parent are locked. Move or remove them first.",
-      "has_children_delete": "Remove the tags nested under this one first"
+      "has_children_delete": "Remove the tags nested under this one first",
+      "visibility_field": "Sidebar visibility",
+      "visibility": {
+        "show": "Show",
+        "unread": "Show if unread",
+        "hide": "Hide"
+      }
     },
     "notifications": {
       "test_sound": "Test notification sound",
diff --git a/locales/nl/common.json b/locales/nl/common.json
index f1e9c19e..d2d3b9a0 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -130,6 +130,8 @@
     "demo_reset": "Resetten",
     "demo_tour": "Rondleiding",
     "tags": "Labels",
+    "show_all_tags": "Alles tonen ({count})",
+    "show_fewer_tags": "Minder tonen",
     "folders": "Mappen",
     "mail": "E-mail",
     "nav_label": "Navigatie",
@@ -1038,7 +1040,13 @@
       "no_parent": "Geen bovenliggend label",
       "too_long": "Dit labelpad is te lang (maximaal {max} tekens)",
       "has_children_locked": "Er vallen andere labels onder dit label, dus de naam en het bovenliggende label liggen vast. Verplaats of verwijder ze eerst.",
-      "has_children_delete": "Verwijder eerst de labels die hieronder vallen"
+      "has_children_delete": "Verwijder eerst de labels die hieronder vallen",
+      "visibility_field": "Zichtbaarheid in de zijbalk",
+      "visibility": {
+        "show": "Tonen",
+        "unread": "Tonen bij ongelezen",
+        "hide": "Verbergen"
+      }
     },
     "notifications": {
       "test_sound": "Meldingsgeluid testen",
diff --git a/stores/__tests__/settings-store-keywords.test.ts b/stores/__tests__/settings-store-keywords.test.ts
index 0722ac4c..202e8428 100644
--- a/stores/__tests__/settings-store-keywords.test.ts
+++ b/stores/__tests__/settings-store-keywords.test.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect, beforeEach } from 'vitest';
-import { useSettingsStore, DEFAULT_KEYWORDS, KEYWORD_PALETTE } from '../settings-store';
+import { useSettingsStore, DEFAULT_KEYWORDS, KEYWORD_PALETTE, getKeywordVisibility } from '../settings-store';
 import type { KeywordDefinition } from '../settings-store';
 
 describe('settings-store keywords', () => {
@@ -157,6 +157,17 @@ describe('settings-store keywords', () => {
     });
   });
 
+  describe('getKeywordVisibility', () => {
+    it('treats a tag stored before visibility was configurable as always shown', () => {
+      expect(getKeywordVisibility({ id: 'red', label: 'Red', color: 'red' })).toBe('show');
+    });
+
+    it('returns the stored choice when there is one', () => {
+      expect(getKeywordVisibility({ id: 'red', label: 'Red', color: 'red', visibility: 'unread' })).toBe('unread');
+      expect(getKeywordVisibility({ id: 'red', label: 'Red', color: 'red', visibility: 'hide' })).toBe('hide');
+    });
+  });
+
   describe('nestedTags', () => {
     it('is off by default', () => {
       useSettingsStore.getState().resetToDefaults();
diff --git a/stores/settings-store.ts b/stores/settings-store.ts
index 7d5b2a03..b8afec55 100644
--- a/stores/settings-store.ts
+++ b/stores/settings-store.ts
@@ -101,10 +101,19 @@ export const ALL_DEBUG_CATEGORIES: { id: DebugCategory; labelKey: string }[] = [
   { id: 'contacts', labelKey: 'contacts' },
 ];
 
+/** Whether a tag shows in the sidebar always, only when it has unread mail, or never. */
+export type KeywordVisibility = 'show' | 'hide' | 'unread';
+
 export interface KeywordDefinition {
   id: string;     // Used as JMAP keyword suffix: $label:<id>
   label: string;  // Display name
   color: string;  // Key from KEYWORD_PALETTE
+  visibility?: KeywordVisibility; // Absent on tags stored before this was configurable
+}
+
+/** Resolves the sidebar visibility of a tag, defaulting to always shown. */
+export function getKeywordVisibility(keyword: KeywordDefinition): KeywordVisibility {
+  return keyword.visibility ?? 'show';
 }
 
 export interface SidebarApp {