diff --git a/app/globals.css b/app/globals.css
index 61c4bca47..d2a335eea 100644
--- a/app/globals.css
+++ b/app/globals.css
@@ -423,7 +423,7 @@ button.extension-widget-trigger:focus-visible {
   padding: 3px 12px 8px;
   color: var(--text-muted);
   font-family: var(--font-mono);
-  font-size: 14px;
+  font-size: var(--extension-widget-font-size, 14px);
   line-height: 1.45;
   overflow-wrap: anywhere;
   white-space: pre-wrap;
diff --git a/components/ChatAppearance.test.mjs b/components/ChatAppearance.test.mjs
index ab56bcc1a..157ee5f8f 100644
--- a/components/ChatAppearance.test.mjs
+++ b/components/ChatAppearance.test.mjs
@@ -9,7 +9,7 @@ const settingsPanel = await readFile(new URL("./SettingsPanel.tsx", import.meta.
 const globals = await readFile(new URL("../app/globals.css", import.meta.url), "utf8");
 const chatAppearanceHook = await readFile(new URL("../hooks/useChatAppearance.ts", import.meta.url), "utf8");
 const jiti = createJiti(import.meta.url);
-const { clampChatContentWidth, clampChatContentFontSize } = await jiti.import("../hooks/useChatAppearance.ts");
+const { clampChatContentWidth, clampChatContentFontSize, clampExtensionWidgetFontSize } = await jiti.import("../hooks/useChatAppearance.ts");
 
 const widthVariable = /var\(--chat-content-max-width, 820px\)/g;
 
@@ -49,3 +49,13 @@ test("chat font size preserves the default and bounds stored or supplied values"
   assert.equal(clampChatContentFontSize(18.7), 19);
   assert.equal(clampChatContentFontSize(30), 24);
 });
+
+test("extension widget font size preserves the default and bounds stored or supplied values", () => {
+  for (const value of [undefined, null, "invalid", Infinity, NaN]) {
+    assert.equal(clampExtensionWidgetFontSize(value), 14);
+  }
+  assert.equal(clampExtensionWidgetFontSize(8), 12);
+  assert.equal(clampExtensionWidgetFontSize("18"), 18);
+  assert.equal(clampExtensionWidgetFontSize(18.7), 19);
+  assert.equal(clampExtensionWidgetFontSize(30), 24);
+});
diff --git a/components/SettingsPanel.test.mjs b/components/SettingsPanel.test.mjs
index b5cf79e79..5b006443e 100644
--- a/components/SettingsPanel.test.mjs
+++ b/components/SettingsPanel.test.mjs
@@ -70,9 +70,9 @@ test("groups chat display controls together without row backgrounds", () => {
 
   assert.doesNotMatch(appearanceSection, /settings-chat-content/);
   assert.match(chatSection, /className="settings-chat-options"/);
-  assert.equal((chatSection.match(/className="settings-chat-option(?: |")/g) ?? []).length, 4);
+  assert.equal((chatSection.match(/className="settings-chat-option(?: |")/g) ?? []).length, 5);
   assert.equal((chatSection.match(/<ConfigSwitch/g) ?? []).length, 2);
-  for (const key of ["thinkingExpandedDefault", "chatContentWidth", "chatContentFontSize", "quoteSelection"]) {
+  for (const key of ["thinkingExpandedDefault", "chatContentWidth", "chatContentFontSize", "extensionWidgetFontSize", "quoteSelection"]) {
     assert.match(chatSection, new RegExp(`t\\("settings\\.${key}"\\)`));
   }
   assert.doesNotMatch(panelSource, /ThinkingIcon|settings-thinking-/);
diff --git a/components/SettingsPanel.tsx b/components/SettingsPanel.tsx
index eb1f105e2..82bfac97e 100644
--- a/components/SettingsPanel.tsx
+++ b/components/SettingsPanel.tsx
@@ -10,6 +10,9 @@ import {
   CHAT_CONTENT_FONT_SIZE_DEFAULT,
   CHAT_CONTENT_FONT_SIZE_MAX,
   CHAT_CONTENT_FONT_SIZE_MIN,
+  EXTENSION_WIDGET_FONT_SIZE_DEFAULT,
+  EXTENSION_WIDGET_FONT_SIZE_MAX,
+  EXTENSION_WIDGET_FONT_SIZE_MIN,
   useChatAppearance,
 } from "@/hooks/useChatAppearance";
 import { sendAgentCommand } from "@/lib/agent-client";
@@ -72,7 +75,7 @@ function ThemeIcon({ preference }: { preference: ThemePreference }) {
 function GeneralSettings({ sessionId, onSessionReloaded, quoteSelectionEnabled, onQuoteSelectionChange }: Pick<Props, "sessionId" | "onSessionReloaded" | "quoteSelectionEnabled" | "onQuoteSelectionChange">) {
   const { locale, setLocale, supportedLocales, t } = useI18n();
   const { preference, setThemePreference } = useTheme();
-  const { width: chatContentWidth, setWidth: setChatContentWidth, fontSize, setFontSize } = useChatAppearance();
+  const { width: chatContentWidth, setWidth: setChatContentWidth, fontSize, setFontSize, extensionWidgetFontSize, setExtensionWidgetFontSize } = useChatAppearance();
   const [shellSettings, setShellSettings] = useState<ShellToolSettingsResponse | null>(null);
   const [shellSaving, setShellSaving] = useState(false);
   const [shellError, setShellError] = useState<string | null>(null);
@@ -220,6 +223,34 @@ function GeneralSettings({ sessionId, onSessionReloaded, quoteSelectionEnabled,
               onChange={(event) => setFontSize(Number(event.target.value))}
             />
           </div>
+          <div className="settings-chat-option settings-chat-range-option">
+            <div className="settings-chat-range-header">
+              <label htmlFor="settings-extension-widget-font-size">{t("settings.extensionWidgetFontSize")}</label>
+              <output htmlFor="settings-extension-widget-font-size">{extensionWidgetFontSize}px</output>
+              <ConfigButton
+                variant="ghost"
+                size="small"
+                className="settings-chat-reset"
+                title={t("settings.resetExtensionWidgetFontSize")}
+                aria-label={t("settings.resetExtensionWidgetFontSize")}
+                disabled={extensionWidgetFontSize === EXTENSION_WIDGET_FONT_SIZE_DEFAULT}
+                onClick={() => setExtensionWidgetFontSize(EXTENSION_WIDGET_FONT_SIZE_DEFAULT)}
+              >
+                <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
+                  <path d="M3 12a9 9 0 1 0 9-9 9.75 9.75 0 0 0-6.74 2.74L3 8M3 3v5h5" />
+                </svg>
+              </ConfigButton>
+            </div>
+            <input
+              id="settings-extension-widget-font-size"
+              type="range"
+              min={EXTENSION_WIDGET_FONT_SIZE_MIN}
+              max={EXTENSION_WIDGET_FONT_SIZE_MAX}
+              step={1}
+              value={extensionWidgetFontSize}
+              onChange={(event) => setExtensionWidgetFontSize(Number(event.target.value))}
+            />
+          </div>
           <div className="settings-chat-option settings-chat-switch-option">
             <span>{t("settings.quoteSelection")}</span>
             <ConfigSwitch
diff --git a/hooks/useChatAppearance.ts b/hooks/useChatAppearance.ts
index cb888c447..47212da60 100644
--- a/hooks/useChatAppearance.ts
+++ b/hooks/useChatAppearance.ts
@@ -10,15 +10,21 @@ export const CHAT_CONTENT_FONT_SIZE_DEFAULT = 14;
 export const CHAT_CONTENT_FONT_SIZE_MIN = 12;
 export const CHAT_CONTENT_FONT_SIZE_MAX = 24;
 export const CHAT_CONTENT_FONT_SIZE_STORAGE_KEY = "pi-chat-content-font-size";
+export const EXTENSION_WIDGET_FONT_SIZE_DEFAULT = 14;
+export const EXTENSION_WIDGET_FONT_SIZE_MIN = 12;
+export const EXTENSION_WIDGET_FONT_SIZE_MAX = 24;
+export const EXTENSION_WIDGET_FONT_SIZE_STORAGE_KEY = "pi-extension-widget-font-size";
 
 interface ChatAppearance {
   width: number;
   fontSize: number;
+  extensionWidgetFontSize: number;
 }
 
 const DEFAULT_APPEARANCE: ChatAppearance = {
   width: CHAT_CONTENT_WIDTH_DEFAULT,
   fontSize: CHAT_CONTENT_FONT_SIZE_DEFAULT,
+  extensionWidgetFontSize: EXTENSION_WIDGET_FONT_SIZE_DEFAULT,
 };
 let appearance: ChatAppearance | null = null;
 const listeners = new Set<() => void>();
@@ -35,6 +41,12 @@ export function clampChatContentFontSize(value: unknown): number {
   return Math.max(CHAT_CONTENT_FONT_SIZE_MIN, Math.min(CHAT_CONTENT_FONT_SIZE_MAX, Math.round(size)));
 }
 
+export function clampExtensionWidgetFontSize(value: unknown): number {
+  const size = Number(value ?? EXTENSION_WIDGET_FONT_SIZE_DEFAULT);
+  if (!Number.isFinite(size)) return EXTENSION_WIDGET_FONT_SIZE_DEFAULT;
+  return Math.max(EXTENSION_WIDGET_FONT_SIZE_MIN, Math.min(EXTENSION_WIDGET_FONT_SIZE_MAX, Math.round(size)));
+}
+
 function readStoredPreference(key: string): string | null {
   try {
     return window.localStorage.getItem(key);
@@ -43,10 +55,11 @@ function readStoredPreference(key: string): string | null {
   }
 }
 
-function applyAppearance({ width, fontSize }: ChatAppearance): void {
+function applyAppearance({ width, fontSize, extensionWidgetFontSize }: ChatAppearance): void {
   if (typeof document === "undefined") return;
   document.documentElement.style.setProperty("--chat-content-max-width", `${width}px`);
   document.documentElement.style.setProperty("--chat-content-font-size", `${fontSize}px`);
+  document.documentElement.style.setProperty("--extension-widget-font-size", `${extensionWidgetFontSize}px`);
 }
 
 function getSnapshot(): ChatAppearance {
@@ -55,6 +68,7 @@ function getSnapshot(): ChatAppearance {
     appearance = {
       width: clampChatContentWidth(readStoredPreference(CHAT_CONTENT_WIDTH_STORAGE_KEY)),
       fontSize: clampChatContentFontSize(readStoredPreference(CHAT_CONTENT_FONT_SIZE_STORAGE_KEY)),
+      extensionWidgetFontSize: clampExtensionWidgetFontSize(readStoredPreference(EXTENSION_WIDGET_FONT_SIZE_STORAGE_KEY)),
     };
     applyAppearance(appearance);
   }
@@ -66,15 +80,28 @@ function subscribe(listener: () => void): () => void {
   return () => { listeners.delete(listener); };
 }
 
+function clampByKey(key: keyof ChatAppearance, value: number): number {
+  switch (key) {
+    case "width": return clampChatContentWidth(value);
+    case "fontSize": return clampChatContentFontSize(value);
+    case "extensionWidgetFontSize": return clampExtensionWidgetFontSize(value);
+  }
+}
+
+function storageKeyFor(key: keyof ChatAppearance): string {
+  switch (key) {
+    case "width": return CHAT_CONTENT_WIDTH_STORAGE_KEY;
+    case "fontSize": return CHAT_CONTENT_FONT_SIZE_STORAGE_KEY;
+    case "extensionWidgetFontSize": return EXTENSION_WIDGET_FONT_SIZE_STORAGE_KEY;
+  }
+}
+
 function setPreference(key: keyof ChatAppearance, value: number): void {
-  const nextValue = key === "width" ? clampChatContentWidth(value) : clampChatContentFontSize(value);
+  const nextValue = clampByKey(key, value);
   appearance = { ...getSnapshot(), [key]: nextValue };
   applyAppearance(appearance);
   try {
-    window.localStorage.setItem(
-      key === "width" ? CHAT_CONTENT_WIDTH_STORAGE_KEY : CHAT_CONTENT_FONT_SIZE_STORAGE_KEY,
-      String(nextValue),
-    );
+    window.localStorage.setItem(storageKeyFor(key), String(nextValue));
   } catch {
     // Best-effort browser preference persistence.
   }
@@ -83,8 +110,9 @@ function setPreference(key: keyof ChatAppearance, value: number): void {
 
 const setWidth = (value: number) => setPreference("width", value);
 const setFontSize = (value: number) => setPreference("fontSize", value);
+const setExtensionWidgetFontSize = (value: number) => setPreference("extensionWidgetFontSize", value);
 
 export function useChatAppearance() {
   const snapshot = useSyncExternalStore(subscribe, getSnapshot, () => DEFAULT_APPEARANCE);
-  return { ...snapshot, setWidth, setFontSize };
+  return { ...snapshot, setWidth, setFontSize, setExtensionWidgetFontSize };
 }
diff --git a/lib/i18n/messages/en.ts b/lib/i18n/messages/en.ts
index 632b630ce..232b61ace 100644
--- a/lib/i18n/messages/en.ts
+++ b/lib/i18n/messages/en.ts
@@ -21,6 +21,8 @@ export const enLocale: LocalePlugin = {
     "settings.chatContentFontSize": "Chat font size",
     "settings.resetChatContentWidth": "Reset chat content width",
     "settings.resetChatContentFontSize": "Reset chat font size",
+    "settings.extensionWidgetFontSize": "Extension widget font size",
+    "settings.resetExtensionWidgetFontSize": "Reset extension widget font size",
     "settings.chatContentWidthDescription": "Set the maximum width of messages and the composer.",
     "settings.themeLight": "Light",
     "settings.themeDark": "Dark",
diff --git a/lib/i18n/messages/zh-CN.ts b/lib/i18n/messages/zh-CN.ts
index a2f69aa51..550a43f28 100644
--- a/lib/i18n/messages/zh-CN.ts
+++ b/lib/i18n/messages/zh-CN.ts
@@ -21,6 +21,8 @@ export const zhCNLocale: LocalePlugin = {
     "settings.chatContentFontSize": "聊天字体大小",
     "settings.resetChatContentWidth": "重置聊天内容宽度",
     "settings.resetChatContentFontSize": "重置聊天字体大小",
+    "settings.extensionWidgetFontSize": "扩展组件字体大小",
+    "settings.resetExtensionWidgetFontSize": "重置扩展组件字体大小",
     "settings.chatContentWidthDescription": "设置消息内容和输入框的最大宽度。",
     "settings.themeLight": "浅色",
     "settings.themeDark": "深色",
diff --git a/lib/i18n/messages/zh-TW.ts b/lib/i18n/messages/zh-TW.ts
index c8ddcd17d..f5d6f128a 100644
--- a/lib/i18n/messages/zh-TW.ts
+++ b/lib/i18n/messages/zh-TW.ts
@@ -21,6 +21,8 @@ export const zhTWLocale: LocalePlugin = {
     "settings.chatContentFontSize": "聊天字體大小",
     "settings.resetChatContentWidth": "重設聊天內容寬度",
     "settings.resetChatContentFontSize": "重設聊天字體大小",
+    "settings.extensionWidgetFontSize": "擴充功能小工具字體大小",
+    "settings.resetExtensionWidgetFontSize": "重設擴充功能小工具字體大小",
     "settings.chatContentWidthDescription": "設定訊息內容和輸入框的最大寬度。",
     "settings.themeLight": "淺色",
     "settings.themeDark": "深色",