diff --git a/muxplex/frontend/index.html b/muxplex/frontend/index.html
index 1a38ad3..4d4c773 100644
--- a/muxplex/frontend/index.html
+++ b/muxplex/frontend/index.html
@@ -10,7 +10,7 @@
   <link rel="icon" type="image/x-icon" href="/favicon.ico" />
   <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32.png" />
   <link rel="apple-touch-icon" href="/apple-touch-icon.png" />
-  <link rel="stylesheet" href="/vendor/xterm.css" />
+  <!-- ghostty-web uses canvas rendering, no CSS needed -->
   <link rel="stylesheet" href="/style.css" />
   <title>muxplex</title>
 </head>
@@ -269,8 +269,7 @@
   </dialog>
 
   <!-- ── Scripts ──────────────────────────────────────────────────────────── -->
-  <script src="/vendor/xterm.js"></script>
-  <script src="/vendor/xterm-addon-fit.js"></script>
+  <script src="/vendor/ghostty-web.js"></script>
   <script src="/vendor/xterm-addon-web-links.js"></script>
   <script src="/vendor/xterm-addon-search.js"></script>
   <script src="/vendor/addon-image.js"></script>
diff --git a/muxplex/tests/test_frontend_js.py b/muxplex/tests/test_frontend_js.py
index 881a92b..bd4a19a 100644
--- a/muxplex/tests/test_frontend_js.py
+++ b/muxplex/tests/test_frontend_js.py
@@ -5,10 +5,37 @@ import re
 
 JS_PATH = pathlib.Path(__file__).parent.parent / "frontend" / "app.js"
 TERMINAL_JS_PATH = pathlib.Path(__file__).parent.parent / "frontend" / "terminal.js"
+INDEX_HTML_PATH = pathlib.Path(__file__).parent.parent / "frontend" / "index.html"
 
 # Read once per module — tests are read-only so sharing is safe.
 _JS: str = JS_PATH.read_text()
 _TERMINAL_JS: str = TERMINAL_JS_PATH.read_text()
+_INDEX_HTML: str = INDEX_HTML_PATH.read_text()
+
+
+# ── index.html script tag migration (ghostty-web) ────────────────────
+
+
+def test_index_html_loads_ghostty_web_js() -> None:
+    """index.html must load ghostty-web.js."""
+    assert "ghostty-web.js" in _INDEX_HTML, (
+        "index.html must include a <script> tag for ghostty-web.js"
+    )
+
+
+def test_index_html_no_xterm_js_script() -> None:
+    """index.html must not load xterm.js directly."""
+    assert 'src="/vendor/xterm.js"' not in _INDEX_HTML, (
+        "index.html must not include a <script> tag for xterm.js — use ghostty-web.js instead"
+    )
+
+
+def test_index_html_no_xterm_addon_fit_script() -> None:
+    """index.html must not load xterm-addon-fit.js (ghostty-web bundles fit natively)."""
+    assert "xterm-addon-fit.js" not in _INDEX_HTML, (
+        "index.html must not include a <script> tag for xterm-addon-fit.js — "
+        "ghostty-web bundles fit natively"
+    )
 
 
 # ── Palette state variables must be removed ──────────────────────────────────