diff --git a/src/client/shim.d.ts b/src/client/shim.d.ts
index 166b35e3e368..c6c262e5fa5f 100644
--- a/src/client/shim.d.ts
+++ b/src/client/shim.d.ts
@@ -1,5 +1,7 @@
 declare const __VP_HASH_MAP__: Record<string, string>
-
+declare const __CARBON__: boolean
+declare const __BSA__: boolean
+declare const __ALGOLIA__: boolean
 declare module '*.vue' {
   import { ComponentOptions } from 'vue'
   const comp: ComponentOptions
diff --git a/src/client/theme-default/Layout.vue b/src/client/theme-default/Layout.vue
index c7b820ee33cd..d18d9ad397b4 100644
--- a/src/client/theme-default/Layout.vue
+++ b/src/client/theme-default/Layout.vue
@@ -77,15 +77,18 @@ import NavBar from './components/NavBar.vue'
 import SideBar from './components/SideBar.vue'
 import Page from './components/Page.vue'
 const Home = defineAsyncComponent(() => import('./components/Home.vue'))
-const CarbonAds = defineAsyncComponent(
+
+const NoopComponent = () => null
+
+const CarbonAds = __CARBON__ ? defineAsyncComponent(
   () => import('./components/CarbonAds.vue')
-)
-const BuySellAds = defineAsyncComponent(
+) : NoopComponent
+const BuySellAds = __BSA__ ? defineAsyncComponent(
   () => import('./components/BuySellAds.vue')
-)
-const AlgoliaSearchBox = defineAsyncComponent(
+) : NoopComponent
+const AlgoliaSearchBox = __ALGOLIA__ ? defineAsyncComponent(
   () => import('./components/AlgoliaSearchBox.vue')
-)
+) : NoopComponent
 
 // generic state
 const route = useRoute()
diff --git a/src/node/plugin.ts b/src/node/plugin.ts
index 7bf4d5df695c..a32d6b9c50fd 100644
--- a/src/node/plugin.ts
+++ b/src/node/plugin.ts
@@ -2,7 +2,7 @@ import path from 'path'
 import { Plugin } from 'vite'
 import { SiteConfig, resolveSiteData } from './config'
 import { createMarkdownToVueRenderFn } from './markdownToVue'
-import { APP_PATH, SITE_DATA_REQUEST_PATH } from './alias'
+import { APP_PATH, DEFAULT_THEME_PATH, SITE_DATA_REQUEST_PATH } from './alias'
 import createVuePlugin from '@vitejs/plugin-vue'
 import slash from 'slash'
 import { OutputAsset, OutputChunk } from 'rollup'
@@ -24,7 +24,7 @@ const isPageChunk = (
 
 export function createVitePressPlugin(
   root: string,
-  { configPath, aliases, markdown, site: initialSiteData }: SiteConfig,
+  { configPath, aliases, markdown, themeDir, site }: SiteConfig,
   ssr = false,
   pageToHashMap?: Record<string, string>
 ): Plugin[] {
@@ -35,7 +35,9 @@ export function createVitePressPlugin(
     ssr
   })
 
-  let siteData = initialSiteData
+  let siteData = site
+
+  const isUsingDefaultTheme = themeDir === DEFAULT_THEME_PATH
 
   const vitePressPlugin: Plugin = {
     name: 'vitepress',
@@ -43,7 +45,14 @@ export function createVitePressPlugin(
     config() {
       return {
         alias: aliases,
-        transformInclude: /\.md$/
+        transformInclude: /\.md$/,
+        define: isUsingDefaultTheme
+          ? {
+              __CARBON__: !!site.themeConfig.carbonAds?.carbon,
+              __BSA__: !!site.themeConfig.carbonAds?.custom,
+              __ALGOLIA__: !!site.themeConfig.algolia
+            }
+          : {}
       }
     },