diff --git a/public/scripts/openai.js b/public/scripts/openai.js
index a8f1725b3..140b54c93 100644
--- a/public/scripts/openai.js
+++ b/public/scripts/openai.js
@@ -57,6 +57,7 @@ import {
     getSortableDelay,
     getStringHash,
     isDataURL,
+    isValidUrl,
     parseJsonFile,
     resetScrollHeight,
     stringFormat,
@@ -3490,6 +3491,12 @@ async function getStatusOpen() {
         return resultCheckStatus();
     }
 
+    if (oai_settings.chat_completion_source === chat_completion_sources.CUSTOM && !isValidUrl(oai_settings.custom_url)) {
+        console.debug('Invalid endpoint URL of Custom OpenAI API:', oai_settings.custom_url);
+        setOnlineStatus('no_connection');
+        return resultCheckStatus();
+    }
+
     let data = {
         reverse_proxy: oai_settings.reverse_proxy,
         proxy_password: oai_settings.proxy_password,