diff --git a/src/lib/components/editor/MonacoEditor.svelte b/src/lib/components/editor/MonacoEditor.svelte
index 65a57c93..953e40e2 100644
--- a/src/lib/components/editor/MonacoEditor.svelte
+++ b/src/lib/components/editor/MonacoEditor.svelte
@@ -2,11 +2,7 @@
   import { onMount, onDestroy } from 'svelte';
   import { browser } from '$app/environment';
   import { theme } from '$lib/theme.svelte';
-  import {
-    registerTrinoSql,
-    setCompletionDefaultsGetter,
-    TRINO_SQL_LANGUAGE_ID
-  } from '$lib/editor/trinosql';
+  import { TRINO_SQL_LANGUAGE_ID } from '$lib/editor/language-id';
 
   let {
     value = $bindable(),
@@ -134,6 +130,8 @@
   // Guarded by `browser` because SvelteKit evaluates component scripts on the server too.
   const workerImport = browser ? import('monaco-editor/esm/vs/editor/editor.worker?worker') : null;
   const monacoImport = browser ? import('monaco-editor') : null;
+  // The Trino SQL language pulls in the ANTLR parser (~1 MB); load it lazily alongside Monaco.
+  const trinoSqlImport = browser ? import('$lib/editor/trinosql') : null;
 
   function toMonacoTheme(t: string): string {
     return t === 'dark' ? 'vs-dark' : 'vs';
@@ -151,6 +149,7 @@
     };
 
     monaco = await monacoImport!;
+    const { registerTrinoSql, setCompletionDefaultsGetter } = await trinoSqlImport!;
 
     setCompletionDefaultsGetter(() => ({
       catalog: defaultCatalog || undefined,
diff --git a/src/lib/editor/language-id.ts b/src/lib/editor/language-id.ts
new file mode 100644
index 00000000..ecd52a40
--- /dev/null
+++ b/src/lib/editor/language-id.ts
@@ -0,0 +1,3 @@
+// Kept separate from trinosql.ts so it can be imported without pulling in the
+// ANTLR lexer/parser, which are only loaded client-side together with Monaco.
+export const TRINO_SQL_LANGUAGE_ID = 'trinosql';
diff --git a/src/lib/editor/trinosql.ts b/src/lib/editor/trinosql.ts
index ab345730..9db59e6c 100644
--- a/src/lib/editor/trinosql.ts
+++ b/src/lib/editor/trinosql.ts
@@ -6,13 +6,12 @@ import type * as Monaco from 'monaco-editor';
 import { CharStream } from 'antlr4ng';
 import { SqlBaseLexer } from './generated/SqlBaseLexer.js';
 import { tokenMap } from './tokenMap';
+import { TRINO_SQL_LANGUAGE_ID } from './language-id.js';
 import {
   createCompletionProvider,
   type CompletionDefaults
 } from './completion/completion-provider.js';
 
-const LANGUAGE_ID = 'trinosql';
-
 class TrinoSqlTokenizerState implements Monaco.languages.IState {
   clone(): Monaco.languages.IState {
     return new TrinoSqlTokenizerState();
@@ -39,20 +38,20 @@ export interface RegisterOptions {
 }
 
 export function registerTrinoSql(monaco: typeof Monaco, options: RegisterOptions = {}): void {
-  if (monaco.languages.getLanguages().some((lang) => lang.id === LANGUAGE_ID)) {
+  if (monaco.languages.getLanguages().some((lang) => lang.id === TRINO_SQL_LANGUAGE_ID)) {
     return;
   }
 
-  monaco.languages.register({ id: LANGUAGE_ID });
+  monaco.languages.register({ id: TRINO_SQL_LANGUAGE_ID });
 
   if (options.completionEnabled !== false) {
     monaco.languages.registerCompletionItemProvider(
-      LANGUAGE_ID,
+      TRINO_SQL_LANGUAGE_ID,
       createCompletionProvider(monaco, () => defaultsGetter())
     );
   }
 
-  monaco.languages.setTokensProvider(LANGUAGE_ID, {
+  monaco.languages.setTokensProvider(TRINO_SQL_LANGUAGE_ID, {
     getInitialState: () => new TrinoSqlTokenizerState(),
     tokenize: (line: string, state: Monaco.languages.IState) => {
       const inputStream = CharStream.fromString(line);
@@ -73,5 +72,3 @@ export function registerTrinoSql(monaco: typeof Monaco, options: RegisterOptions
     }
   });
 }
-
-export { LANGUAGE_ID as TRINO_SQL_LANGUAGE_ID };