diff --git a/src/lib/utils/codeHighlight.ts b/src/lib/utils/codeHighlight.ts
index fcd8443530..0e33dd3872 100644
--- a/src/lib/utils/codeHighlight.ts
+++ b/src/lib/utils/codeHighlight.ts
@@ -1,5 +1,3 @@
-import { codeToHtml, bundledLanguages } from 'shiki';
-
 /**
  * Map file extensions to Shiki language identifiers.
  * Only extensions whose Shiki lang id differs from the extension itself need explicit entries.
@@ -53,7 +51,97 @@ const EXT_OVERRIDE: Record<string, string> = {
 	jsonl: 'jsonl'
 };
 
-const _langSet = new Set(Object.keys(bundledLanguages));
+// Common extensions that exactly match their Shiki language ID.
+// This replaces the runtime `bundledLanguages` import from shiki, which
+// pulled ~5-10MB of JavaScript into the initial page load just so
+// isCodeFile() could check extension support.
+const KNOWN_LANG_IDS = new Set([
+	'ada',
+	'awk',
+	'bat',
+	'c',
+	'cmake',
+	'clojure',
+	'cpp',
+	'crystal',
+	'css',
+	'd',
+	'dart',
+	'diff',
+	'elixir',
+	'elm',
+	'erlang',
+	'fish',
+	'gleam',
+	'glsl',
+	'go',
+	'groovy',
+	'haml',
+	'haskell',
+	'hlsl',
+	'html',
+	'ini',
+	'java',
+	'javascript',
+	'json',
+	'json5',
+	'jsonc',
+	'jsx',
+	'julia',
+	'kotlin',
+	'latex',
+	'less',
+	'lisp',
+	'log',
+	'lua',
+	'make',
+	'markdown',
+	'matlab',
+	'mdx',
+	'mojo',
+	'nim',
+	'nix',
+	'nushell',
+	'ocaml',
+	'pascal',
+	'perl',
+	'php',
+	'postcss',
+	'powershell',
+	'prisma',
+	'prolog',
+	'proto',
+	'pug',
+	'python',
+	'r',
+	'ruby',
+	'rust',
+	'sass',
+	'scala',
+	'scheme',
+	'scss',
+	'solidity',
+	'sql',
+	'svelte',
+	'swift',
+	'tcl',
+	'terraform',
+	'tex',
+	'toml',
+	'tsx',
+	'typescript',
+	'typst',
+	'v',
+	'vb',
+	'verilog',
+	'vhdl',
+	'vue',
+	'wasm',
+	'wgsl',
+	'xml',
+	'yaml',
+	'zig'
+]);
 
 /**
  * Resolve a file extension to a Shiki language id, or null if not supported.
@@ -62,8 +150,8 @@ export function extToLang(ext: string): string | null {
 	const lower = ext.toLowerCase();
 	// explicit override first
 	if (EXT_OVERRIDE[lower]) return EXT_OVERRIDE[lower];
-	// if the extension itself is a bundled language id (e.g. 'go', 'rust', 'sql', 'toml', ...)
-	if (_langSet.has(lower)) return lower;
+	// if the extension itself is a known language id (e.g. 'go', 'rust', 'sql', 'toml', ...)
+	if (KNOWN_LANG_IDS.has(lower)) return lower;
 	return null;
 }
 
@@ -79,11 +167,16 @@ export function isCodeFile(path: string | null): boolean {
 /**
  * Highlight code using Shiki with dual light/dark themes via CSS variables.
  * Returns an HTML string. Throws on failure.
+ *
+ * Shiki is loaded on demand (dynamic import) to avoid pulling ~5-10MB of
+ * JavaScript into the initial page bundle. Since this function is already
+ * async, callers are completely unaffected by the change.
  */
 export async function highlightCode(code: string, filePath: string): Promise<string> {
 	const ext = filePath.split('.').pop()?.toLowerCase() ?? '';
 	const lang = extToLang(ext) ?? 'text';
 
+	const { codeToHtml } = await import('shiki');
 	return await codeToHtml(code, {
 		lang,
 		themes: {
@@ -93,3 +186,4 @@ export async function highlightCode(code: string, filePath: string): Promise<str
 		defaultColor: 'light'
 	});
 }
+