diff --git a/g4f/gui/client/html/index.html b/g4f/gui/client/html/index.html
index bb472706..c15584b8 100644
--- a/g4f/gui/client/html/index.html
+++ b/g4f/gui/client/html/index.html
@@ -118,9 +118,13 @@
                 <div class="field">
                     <select name="model" id="model">
                         <option value="gpt-3.5-turbo" selected>gpt-3.5</option>
-                        <option value="gpt-4">gpt-4</option>
                         <option value="gpt-3.5-turbo-0613">gpt-3.5 fast</option>
                         <option value="gpt-3.5-turbo-16k">gpt-3.5 16k</option>
+                        <option value="gpt-3.5-turbo-16k-0613">gpt-3.5 16k fast</option>
+                        <option value="gpt-4" selected>gpt-4</option>
+                        <option value="gpt-4-0613">gpt-4 fast</option>
+                        <option value="gpt-4-32k">gpt-4 32k</option>
+                        <option value="gpt-4-32k-0613">gpt-4 32k fast</option>
                     </select>
                 </div>
                 <div class="field">
diff --git a/g4f/gui/server/backend.py b/g4f/gui/server/backend.py
index cf1f9428..a76ca12b 100644
--- a/g4f/gui/server/backend.py
+++ b/g4f/gui/server/backend.py
@@ -33,17 +33,17 @@ class Backend_Api:
             conversation    = request.json['meta']['content']['conversation']
             prompt          = request.json['meta']['content']['parts'][0]
             model           = request.json['model']
-            provider        = get_provider(request.json.get('provider'))
+            provider        = request.json.get('provider').split("g4f.Provider.")[1]
             
             messages = special_instructions[jailbreak] + conversation + search(internet_access, prompt) + [prompt]
             
             def stream():
                 if provider:
                     answer = g4f.ChatCompletion.create(model=model,
-                                                       provider=g4f.Provider.ProviderUtils.convert.get(provider), messages=messages, stream=True)
+                                                       provider=get_provider(provider), messages=messages, stream=True)
                 else:
                     answer = g4f.ChatCompletion.create(model=model,
-                                                        messages=messages, stream=True)
+                                                       messages=messages, stream=True)
                 
                 for token in answer:
                     yield token
diff --git a/g4f/gui/server/provider.py b/g4f/gui/server/provider.py
index 230b5f5f..11202d38 100644
--- a/g4f/gui/server/provider.py
+++ b/g4f/gui/server/provider.py
@@ -3,17 +3,12 @@ from g4f import BaseProvider
 
 
 def get_provider(provider: str) -> BaseProvider | None:
-    
     if isinstance(provider, str):
         print(provider)
         if provider == 'g4f.Provider.Auto':
             return None
         
-        if provider in g4f.Provider.ProviderUtils.convert:
-            return g4f.Provider.ProviderUtils.convert[provider]
-        
-        else:
-            return None
+        return g4f.Provider.ProviderUtils.convert.get(provider)
         
     else:
         return None
diff --git a/g4f/models.py b/g4f/models.py
index ced8e290..9be8f459 100644
--- a/g4f/models.py
+++ b/g4f/models.py
@@ -65,14 +65,16 @@ gpt_35_turbo = Model(
     name          = 'gpt-3.5-turbo',
     base_provider = 'openai',
     best_provider = RetryProvider([
-        DeepAi, ChatgptLogin, ChatgptAi, GptGo, AItianhu, Aichat, AItianhuSpace, Myshell, Aibn, FreeGpt, Ylokh
+        DeepAi, Aivvm, ChatgptLogin, ChatgptAi, GptGo, AItianhu, Aichat, AItianhuSpace, Myshell, Aibn, FreeGpt, Ylokh
     ])
 )
 
 gpt_4 = Model(
     name          = 'gpt-4',
     base_provider = 'openai',
-    best_provider = Bing
+    best_provider = RetryProvider([
+        Aivvm, Bing
+    ])
 )
 
 # Bard
@@ -165,27 +167,32 @@ gpt_35_turbo_16k = Model(
 
 gpt_35_turbo_16k_0613 = Model(
     name          = 'gpt-3.5-turbo-16k-0613',
-    base_provider = 'openai')
+    base_provider = 'openai',
+    best_provider = Aivvm
+)
 
 gpt_35_turbo_0613 = Model(
     name          = 'gpt-3.5-turbo-0613',
     base_provider = 'openai',
-    best_provider=Aivvm
+    best_provider = Aivvm
 )
 
 gpt_4_0613 = Model(
     name          = 'gpt-4-0613',
-    base_provider = 'openai'
+    base_provider = 'openai',
+    best_provider = Aivvm
 )
 
 gpt_4_32k = Model(
     name          = 'gpt-4-32k',
-    base_provider = 'openai'
+    base_provider = 'openai',
+    best_provider = Aivvm
 )
 
 gpt_4_32k_0613 = Model(
     name          = 'gpt-4-32k-0613',
-    base_provider = 'openai'
+    base_provider = 'openai',
+    best_provider = Aivvm
 )
 
 text_ada_001 = Model(