diff --git a/web/app/components/base/chat/chat-with-history/hooks.tsx b/web/app/components/base/chat/chat-with-history/hooks.tsx
index d4fa170e4c60d0..a67cc3cd885387 100644
--- a/web/app/components/base/chat/chat-with-history/hooks.tsx
+++ b/web/app/components/base/chat/chat-with-history/hooks.tsx
@@ -173,7 +173,7 @@ export const useChatWithHistory = (installedAppInfo?: InstalledApp) => {
     const conversationInputs: Record<string, any> = {}
 
     inputsForms.forEach((item: any) => {
-      conversationInputs[item.variable] = item.default || ''
+      conversationInputs[item.variable] = item.default || null
     })
     handleNewConversationInputsChange(conversationInputs)
   }, [handleNewConversationInputsChange, inputsForms])
diff --git a/web/app/components/base/chat/embedded-chatbot/hooks.tsx b/web/app/components/base/chat/embedded-chatbot/hooks.tsx
index 631d3b56bc0232..0a8bc0993f997c 100644
--- a/web/app/components/base/chat/embedded-chatbot/hooks.tsx
+++ b/web/app/components/base/chat/embedded-chatbot/hooks.tsx
@@ -159,7 +159,7 @@ export const useEmbeddedChatbot = () => {
     const conversationInputs: Record<string, any> = {}
 
     inputsForms.forEach((item: any) => {
-      conversationInputs[item.variable] = item.default || ''
+      conversationInputs[item.variable] = item.default || null
     })
     handleNewConversationInputsChange(conversationInputs)
   }, [handleNewConversationInputsChange, inputsForms])