Azure OpenAI: Why am I getting “Too many images in request (max 10)” when I’m sending a PDF, not images?

Question

Azure OpenAI: Why am I getting “Too many images in request (max 10)” when I’m sending a PDF, not images?

Nawaf Alabdullah 0

I submit a single PDF (~20 pages) to Azure OpenAI and receive this error:

{
  "error": {
    "type": "invalid_request_error",
    "message": "Too many images in request: 20, maximum allowed: 10."
  }
}

I am not explicitly sending images, so I’m trying to understand why an image limit is being enforced on a PDF input.

I'm using GPT-4.1 with the responses API.

Manas Mohanty 16,835 Microsoft External Staff Moderator

Hi Nawaf Alabdullah

It seems you are facing invalid request error on sending a pdf file with 20 pages and Response Api.

I think scanned pdf file are being counted as image here hinting toward Max page limit is 10 for pdf file.

You can split the 20-page pdf into smaller pdfs and pass it to chat completion model.


from PyPDF2 import PdfReader, PdfWriter

def split_pdf(input_path, pages_per_split=5):
    reader = PdfReader(input_path)
    total_pages = len(reader.pages)
    for i in range(0, total_pages, pages_per_split):
        writer = PdfWriter()
        for j in range(i, min(i + pages_per_split, total_pages)):
            writer.add_page(reader.pages[j])
        output_path = f"split_{i + 1}_to_{min(i + pages_per_split, total_pages)}.pdf"
        with open(output_path, "wb") as output_file:
            writer.write(output_file)
        print(f"Created: {output_path}")

# Example usage
split_pdf("your_20_page_file.pdf", pages_per_split=5)

Thank you

Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-08-26T04:12:47.5433333+00:00

Hi Nawaf Alabdullah

Could you consider the workaround of splitting 20 pages pdf as smaller 5-page pdf as answer.

Thank you
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-08-27T04:59:37.7966667+00:00

Hi Nawaf Alabdullah

We could not hear from you. Hope you appreciated the inputs.

Thank you
bhhsieh 0 Reputation points

2025-09-10T07:59:07.6333333+00:00

Hi @Manas Mohanty ,

I received the same error, but I found that it says we can upload up to 100 pages and 32MB in a single request to the API.
How can I realized that?
https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/responses?tabs=python-key#file-input
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-09-10T16:14:48.04+00:00

Hi bhhsieh

Thank you for inputs.

Yes, 100 pages on max and 32 MB max in Single request.

I gave above work around of splitting the larger pdf to smaller pdf based on assumption that his total file size was exceeding 32 MB.

Hi Nawaf Alabdullah, please correct me if I was wrong on my assumption.

Thank you
bhhsieh 0 Reputation points

2025-09-11T01:58:51.1066667+00:00

Hi @Manas Mohanty ,Thank you for your reply.

The file size of my PDF is small than 10MB, and it has 29 pages.

However, I still got an error which says "Too many images in request: 29, maximum allowed: 10.".

Do you have any idea how it happens?
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-09-11T02:35:22.86+00:00

bhhsieh

Reviewing with product group internally on this limitation.

Thank you for your inputs.

1 answer

Your answer

Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-08-25T04:05:20.6233333+00:00

Hi Nawaf Alabdullah

It seems you are facing invalid request error on sending a pdf file with 20 pages and Response Api.

I think scanned pdf file are being counted as image here hinting toward Max page limit is 10 for pdf file.

You can split the 20-page pdf into smaller pdfs and pass it to chat completion model.

from PyPDF2 import PdfReader, PdfWriter def split_pdf(input_path, pages_per_split=5): reader = PdfReader(input_path) total_pages = len(reader.pages) for i in range(0, total_pages, pages_per_split): writer = PdfWriter() for j in range(i, min(i + pages_per_split, total_pages)): writer.add_page(reader.pages[j]) output_path = f"split_{i + 1}_to_{min(i + pages_per_split, total_pages)}.pdf" with open(output_path, "wb") as output_file: writer.write(output_file) print(f"Created: {output_path}") # Example usage split_pdf("your_20_page_file.pdf", pages_per_split=5)

Thank you
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-08-26T04:12:47.5433333+00:00

Hi Nawaf Alabdullah

Could you consider the workaround of splitting 20 pages pdf as smaller 5-page pdf as answer.

Thank you
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-08-27T04:59:37.7966667+00:00

Hi Nawaf Alabdullah

We could not hear from you. Hope you appreciated the inputs.

Thank you
bhhsieh 0 Reputation points

2025-09-10T07:59:07.6333333+00:00

Hi @Manas Mohanty ,

I received the same error, but I found that it says we can upload up to 100 pages and 32MB in a single request to the API.
How can I realized that?
https://learn.microsoft.com/en-us/azure/ai-foundry/openai/how-to/responses?tabs=python-key#file-input
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-09-10T16:14:48.04+00:00

Hi bhhsieh

Thank you for inputs.

Yes, 100 pages on max and 32 MB max in Single request.

I gave above work around of splitting the larger pdf to smaller pdf based on assumption that his total file size was exceeding 32 MB.

Hi Nawaf Alabdullah, please correct me if I was wrong on my assumption.

Thank you
bhhsieh 0 Reputation points

2025-09-11T01:58:51.1066667+00:00

Hi @Manas Mohanty ,Thank you for your reply.

The file size of my PDF is small than 10MB, and it has 29 pages.

However, I still got an error which says "Too many images in request: 29, maximum allowed: 10.".

Do you have any idea how it happens?
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-09-11T02:35:22.86+00:00

bhhsieh

Reviewing with product group internally on this limitation.

Thank you for your inputs.

Answer 1

Manas Mohanty 16,835 Microsoft External Staff Moderator

Hi Nawaf Alabdullah and bhhsieh,

100 pages, 32 MB max file limit is for Text based pdfs.

Product group tested 160-page text only pdf successfully. In case they include only images, it is failing with above error.

Successfully, tested a GPT 4.1 Response API endpoint with 10 MB file pdf with both text and image (12 pages)

So, it seems the constraint is with image only pdfs

PG team is working increase the limit of 10 pages to 100 pages

Suggesting splitting image only pdfs under 10 pages for now.

Thank you

Nawaf Alabdullah 0 Reputation points

2025-09-12T20:19:37.6+00:00

Hi Manas, I'm not sure why this is an issue in Azure since, in the OpenAI API we were able to do send PDFs that have multiple pages and images.
Manas Mohanty 16,835 Reputation points Microsoft External Staff Moderator

2025-09-15T01:17:38.31+00:00

Hi Nawaf Alabdullah

Confirmed from product group, it is an issue from Azure OpenAI side.

They are planning to increase the default image limit to 100.

Please take a minute to accept above answer if you were happy with investigation.

Thank you

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Azure OpenAI: Why am I getting “Too many images in request (max 10)” when I’m sending a PDF, not images?

1 answer

Your answer