VBA code gives a timeout with gpt-4 model but works fine with gpt-3.5-turbo

I am making http requests in excel vba - macro.

My code is simple:

Set http = CreateObject(“WinHttp.WinHttpRequest.5.1”)

apiEndpoint = “https://api.openai.com/v1/chat/completions

With http
.Open “POST”, apiEndpoint, False
.setRequestHeader “Content-Type”, “application/json”
.setRequestHeader “Authorization”, "Bearer " & apiKey
.send requestBody
response = .responseText
End With

It works fine with model gpt-3.5-turbo but fails with model gpt-4.
gpt-4 model returns me run-rime error - ‘The operation timed out’

There is no gpt-4 response returned. The code fails at ‘.send requestBody’.

Only difference in the code is string “gpt-3.5-turbo” or “gpt-4”.

The role: system works also with gpt-4. It returns me the response that is expected.

The role : user gives the timed out - error.

What can cause this and how to solve it?

ps. I have read GPT-4 model: frequent No Reply (TimeOut) and it does not confirm to me if the problem is the same or not.

br, petri

I managed to resolve it with help of chatGPT :slight_smile:

I had to increase the http timeout by .setTimeouts 90000, 90000, 90000, 90000.

br, petri

1 Like


I have another issue and since you are doing this in VBA you might be able to help me. Seems as I am missing something in the requestBody…

I am moving from

'Const API_ENDPOINT As String = “https://api.openai.com/v1/completions


Const API_ENDPOINT As String = “https://api.openai.com/v1/chat/completions

And from:

’ Const MODEL As String = “text-davinci-003”


Const MODEL As String = “gpt-4”

Dim requestBody As String
requestBody = "{" & _
    """model"": """ & MODEL & """," & _
    """prompt"": """ & prompt & """," & _
    """max_tokens"": " & MAX_TOKENS & "," & _
    """temperature"": " & TEMPERATURE & _

' Open and send the HTTP request
With httpRequest
    .Open "POST", API_ENDPOINT, False
    .SetRequestHeader "Content-Type", "application/json"
    .SetRequestHeader "Authorization", "Bearer " & ApiKey_OpenAI
    .Send (requestBody)
End With

Appreciate if you can share a snippet of your code. Thanks!

Your JSONs must look like these:
{“model”:“gpt-4”, “messages”: [{“role”:“system”,“content”: MESSAGE CONTENT}]}
{“model”:“gpt-4”, “messages”: [{“role”:“user”,“content”: MESSAGE CONTENT}]}