diff --git a/app/main.py b/app/main.py
index d6f528c..0742360 100644
--- a/app/main.py
+++ b/app/main.py
@@ -152,10 +152,10 @@ body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;backgrou
 
 @app.exception_handler(404)
 async def not_found_handler(request: Request, exc):
-    """Styled 404 page matching the FlowDeck dark theme."""
-    from fastapi.responses import HTMLResponse
-    # API routes should get JSON, not HTML
-    if request.url.path.startswith("/api/") or request.url.path.startswith("/board/api/"):
+    """Redirect 404 HTML pages to /workspaces. API routes still get JSON."""
+    # Preserve JSON 404 for all API-like paths (including /db/xxx/api)
+    if "/api" in request.url.path:
         from fastapi.responses import JSONResponse
         return JSONResponse({"detail": "Not found"}, status_code=404)
-    return HTMLResponse(NOT_FOUND_HTML, status_code=404)
+    from fastapi.responses import RedirectResponse
+    return RedirectResponse("/workspaces", status_code=302)
diff --git a/tests/test_app.py b/tests/test_app.py
index 0a2e3a1..33a9a80 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -1950,11 +1950,10 @@ def test_create_page_defaults_to_untitled(client):
 
 
 def test_styled_404_page(client):
-    """Unknown routes return a styled 404 HTML page."""
+    """Unknown routes redirect to /workspaces."""
     resp = client.get("/this-does-not-exist-xyz", follow_redirects=False)
-    assert resp.status_code == 404
-    assert "404" in resp.text
-    assert "FlowDeck" in resp.text
+    assert resp.status_code == 302
+    assert resp.headers.get("location") == "/workspaces"
 
 
 def test_api_404_returns_json(client):