diff --git a/libretranslate/app.py b/libretranslate/app.py
index a468fe7..bd71404 100644
--- a/libretranslate/app.py
+++ b/libretranslate/app.py
@@ -283,7 +283,8 @@ def create_app(args):
             get_api_key_link=args.get_api_key_link,
             web_version=os.environ.get("LT_WEB") is not None,
             version=get_version(),
-            swagger_url=SWAGGER_URL
+            swagger_url=SWAGGER_URL,
+            url_prefix=args.url_prefix
         )
 
     @bp.get("/javascript-licenses")
diff --git a/libretranslate/static/js/app.js b/libretranslate/static/js/app.js
index 3e9129d..6957b04 100644
--- a/libretranslate/static/js/app.js
+++ b/libretranslate/static/js/app.js
@@ -1,7 +1,6 @@
 // @license magnet:?xt=urn:btih:0b31508aeb0634b347b8270c7bee4d411b5d4109&dn=agpl-3.0.txt AGPL-3.0
 // API host/endpoint
-//var BaseUrl = window.location.protocol + "//" + window.location.host + window.location.pathname.length > 1 ? window.location.pathname : "" ;
-var BaseUrl = window.location.href.slice(0, -1)
+var BaseUrl = window.location.protocol + "//" + window.location.host + url_prefix ;
 var htmlRegex = /<(.*)>.*?|<(.*)\/>/;
 document.addEventListener('DOMContentLoaded', function(){
     var sidenavElems = document.querySelectorAll('.sidenav');
diff --git a/libretranslate/templates/index.html b/libretranslate/templates/index.html
index eafcc68..6061fd1 100644
--- a/libretranslate/templates/index.html
+++ b/libretranslate/templates/index.html
@@ -7,6 +7,9 @@
 	<link rel="shortcut icon" href="{{ url_for('static', filename='favicon.ico') }}">
 	<meta name="description" content="Free and Open Source Machine Translation API. 100% self-hosted, offline capable and easy to setup. Run your own API server in just a few minutes.">
 	<meta name="keywords" content="translation,api">
+	<script type="text/javascript">
+		var url_prefix = "{{ url_prefix }}"
+	</script>
 
 	<link rel="preload" href="{{ url_for('static', filename='icon.svg') }}" as="image" />
 	<link rel="preload" href="{{ url_for('static', filename='js/vue@2.js') }}" as="script">