withastro · florian-lefebvre · Mar 2, 2026 · Feb 26, 2026 · Feb 26, 2026 · Feb 26, 2026
diff --git a/.changeset/kind-hairs-report.md b/.changeset/kind-hairs-report.md
@@ -0,0 +1,5 @@
+---
+'astro': major
+---
+
+Changes TypeScript configuration - ([v6 upgrade guidance](https://v6.docs.astro.build/en/guides/upgrade-to/v6/#changed-typescript-configuration))
diff --git a/.github/scripts/bundle-size.mjs b/.github/scripts/bundle-size.mjs
@@ -75,7 +75,7 @@ async function bundle(files) {
 		bundle: true,
 		minify: true,
 		sourcemap: false,
-		target: ['es2018'],
+		target: ['esnext'],
 		outdir: 'out',
 		external: ['astro:*', 'aria-query', 'axobject-query'],
 		metafile: true,

diff --git a/benchmark/packages/adapter/tsconfig.json b/benchmark/packages/adapter/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/benchmark/packages/timer/tsconfig.json b/benchmark/packages/timer/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/examples/portfolio/src/components/Nav.astro b/examples/portfolio/src/components/Nav.astro
@@ -124,7 +124,7 @@ const isCurrentPage = (href: string) => {
 			};
 
 			// Toggle menu visibility when the menu button is clicked.
-			btn.addEventListener('click', () => setExpanded(menu.hidden));
+			btn.addEventListener('click', () => setExpanded(menu.hidden === true));
 
 			// Hide menu button for large screens.
 			const handleViewports = (e: MediaQueryList | MediaQueryListEvent) => {

diff --git a/examples/toolbar-app/tsconfig.json b/examples/toolbar-app/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "extends": "astro/tsconfigs/strict",
   "compilerOptions": {
-    "outDir": "dist",
-    "rootDir": "src"
+    "outDir": "./dist",
+    "rootDir": "./src"
   }
 }
diff --git a/packages/astro-prism/tsconfig.json b/packages/astro-prism/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/astro-rss/tsconfig.json b/packages/astro-rss/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/astro/src/vite-plugin-config-alias/README.md b/packages/astro/src/vite-plugin-config-alias/README.md
@@ -7,9 +7,8 @@ Consider the following example configuration:
 ```
 {
   "compilerOptions": {
-    "baseUrl": "src",
     "paths": {
-      "components:*": ["components/*.astro"]
+      "components:*": ["src/components/*.astro"]
     }
   }
 }

diff --git a/packages/astro/test/fixtures/alias-tsconfig/tsconfig.json b/packages/astro/test/fixtures/alias-tsconfig/tsconfig.json
@@ -1,5 +1,6 @@
 {
   "compilerOptions": {
+    // TODO: remove when upgrading to TS 6
     "baseUrl": ".",
     "paths": {
       "@components/*": [

diff --git a/packages/astro/test/fixtures/core-image-base/tsconfig.json b/packages/astro/test/fixtures/core-image-base/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/strict",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": [
         "src/assets/*"

diff --git a/packages/astro/test/fixtures/core-image-deletion/tsconfig.json b/packages/astro/test/fixtures/core-image-deletion/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/astro/test/fixtures/core-image-infersize/tsconfig.json b/packages/astro/test/fixtures/core-image-infersize/tsconfig.json
@@ -1,8 +1,5 @@
 {
   "extends": "astro/tsconfigs/base",
-  "compilerOptions": {
-    "baseUrl": ".",
-  },
   "include": [".astro/types.d.ts", "**/*"],
   "exclude": ["dist"]
 }
diff --git a/packages/astro/test/fixtures/core-image-layout/tsconfig.json b/packages/astro/test/fixtures/core-image-layout/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/astro/test/fixtures/core-image-picture-emit-file/tsconfig.json b/packages/astro/test/fixtures/core-image-picture-emit-file/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/strict",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": [
         "src/assets/*"

diff --git a/packages/astro/test/fixtures/core-image-remark-imgattr/tsconfig.json b/packages/astro/test/fixtures/core-image-remark-imgattr/tsconfig.json
@@ -1,8 +1,5 @@
 {
   "extends": "astro/tsconfigs/base",
-  "compilerOptions": {
-    "baseUrl": ".",
-  },
   "include": [".astro/types.d.ts", "**/*"],
   "exclude": ["dist"]
 }
diff --git a/packages/astro/test/fixtures/core-image-ssg/tsconfig.json b/packages/astro/test/fixtures/core-image-ssg/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/astro/test/fixtures/core-image-svg-optimized/tsconfig.json b/packages/astro/test/fixtures/core-image-svg-optimized/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/strict",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": [
         "src/assets/*"

diff --git a/packages/astro/test/fixtures/core-image-svg/tsconfig.json b/packages/astro/test/fixtures/core-image-svg/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/strict",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": [
         "src/assets/*"

diff --git a/packages/astro/test/fixtures/core-image-unconventional-settings/tsconfig.json b/packages/astro/test/fixtures/core-image-unconventional-settings/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/astro/test/fixtures/core-image/tsconfig.json b/packages/astro/test/fixtures/core-image/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/strict",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": [
         "src/assets/*"

diff --git a/packages/astro/test/fixtures/custom-renderer/tsconfig.json b/packages/astro/test/fixtures/custom-renderer/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "@custom-renderer/*": ["src/custom-renderer/*"]
     },

diff --git a/packages/astro/test/fixtures/svg-deduplication/tsconfig.json b/packages/astro/test/fixtures/svg-deduplication/tsconfig.json
@@ -1,7 +1,6 @@
 {
 	"extends": "../../../tsconfigs/strictest.json",
 	"compilerOptions": {
-		"baseUrl": ".",
 		"paths": {
 			"~/*": ["./src/*"]
 		}

diff --git a/packages/astro/tsconfigs/base.json b/packages/astro/tsconfigs/base.json
@@ -26,7 +26,9 @@
     // Allow JavaScript files to be imported
     "allowJs": true,
     // Allow JSX files (or files that are internally considered JSX, like Astro files) to be imported inside `.js` and `.ts` files.
-    "jsx": "preserve"
+    "jsx": "preserve",
+    "types": ["node"],
+    "libReplacement": false
   },
   "exclude": ["${configDir}/dist"],
   "include": ["${configDir}/.astro/types.d.ts", "${configDir}/**/*"]

diff --git a/packages/create-astro/tsconfig.json b/packages/create-astro/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/db/tsconfig.json b/packages/db/tsconfig.json
@@ -3,6 +3,7 @@
   "include": ["src"],
   "exclude": ["src/runtime/virtual.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/db/tsconfig.virtual.json b/packages/db/tsconfig.virtual.json
@@ -7,6 +7,7 @@
   "extends": "../../tsconfig.base.json",
   "files": ["./src/runtime/virtual.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist/_internal"
   }
 }
diff --git a/packages/integrations/alpinejs/tsconfig.json b/packages/integrations/alpinejs/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/cloudflare/tsconfig.json b/packages/integrations/cloudflare/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src", "virtual.d.ts", "types.d.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/markdoc/test/fixtures/image-assets-custom/tsconfig.json b/packages/integrations/markdoc/test/fixtures/image-assets-custom/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/integrations/markdoc/test/fixtures/image-assets/tsconfig.json b/packages/integrations/markdoc/test/fixtures/image-assets/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/integrations/markdoc/tsconfig.json b/packages/integrations/markdoc/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/mdx/test/fixtures/mdx-images/src/pages/content-collection.astro b/packages/integrations/mdx/test/fixtures/mdx-images/src/pages/content-collection.astro
@@ -1,6 +1,6 @@
 ---
 import { getEntry, render } from 'astro:content';
-import MyImage from 'src/components/MyImage.astro';
+import MyImage from '../components/MyImage.astro';
 
 const entry = await getEntry('blog', 'entry');
 const { Content } = await render(entry)

diff --git a/packages/integrations/mdx/test/fixtures/mdx-images/src/pages/esm-import.astro b/packages/integrations/mdx/test/fixtures/mdx-images/src/pages/esm-import.astro
@@ -1,5 +1,5 @@
 ---
-import MyImage from 'src/components/MyImage.astro';
+import MyImage from '../components/MyImage.astro';
 import MDX from '../components/Component.mdx';
 ---
 

diff --git a/packages/integrations/mdx/test/fixtures/mdx-images/tsconfig.json b/packages/integrations/mdx/test/fixtures/mdx-images/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "extends": "astro/tsconfigs/base",
   "compilerOptions": {
-    "baseUrl": ".",
     "paths": {
       "~/assets/*": ["src/assets/*"]
     },

diff --git a/packages/integrations/mdx/tsconfig.json b/packages/integrations/mdx/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/netlify/tsconfig.json b/packages/integrations/netlify/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src", "virtual.d.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/node/tsconfig.json b/packages/integrations/node/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src", "virtual.d.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/partytown/tsconfig.json b/packages/integrations/partytown/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/preact/tsconfig.json b/packages/integrations/preact/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/react/tsconfig.json b/packages/integrations/react/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src", "env.d.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/sitemap/tsconfig.json b/packages/integrations/sitemap/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/solid/tsconfig.json b/packages/integrations/solid/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/svelte/tsconfig.json b/packages/integrations/svelte/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist",
     "verbatimModuleSyntax": false
   }

diff --git a/packages/integrations/vercel/tsconfig.json b/packages/integrations/vercel/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src", "virtual.d.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/integrations/vue/tsconfig.json b/packages/integrations/vue/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../../tsconfig.base.json",
   "include": ["src", "env.d.ts"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist",
     "verbatimModuleSyntax": false
   }

diff --git a/packages/internal-helpers/tsconfig.json b/packages/internal-helpers/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../tsconfig.base.json",
   "include": ["src"],
   "compilerOptions": {
+    "rootDir": "./src",
     "outDir": "./dist"
   }
 }
diff --git a/packages/language-tools/astro-check/tsconfig.json b/packages/language-tools/astro-check/tsconfig.json
@@ -1,8 +1,8 @@
 {
   "extends": "../tsconfig.json",
   "compilerOptions": {
-    "rootDir": "src",
-    "outDir": "dist",
+    "rootDir": "./src",
+    "outDir": "./dist",
     "emitDeclarationOnly": false,
     "sourceMap": true,
     "module": "ES2022",