File inputs

File inputs#

Learn how to use PDF files as inputs to the OpenAI API.

OpenAI models with vision capabilities can also accept PDF files as input. Provide PDFs either as Base64-encoded data or as file IDs obtained after uploading files to the /v1/files endpoint through the API or dashboard under storage.

How it works#

To help models understand PDF content, we put into the model’s context both the extracted text and an image of each page. The model can then use both the text and the images to generate a response. This is useful, for example, if diagrams contain key information that isn’t in the text.

Uploading files#

In the example below, we first upload a PDF using the Files API, then reference its file ID in an API request to the model.

Upload a file to use in a response

from openai import OpenAI
client = OpenAI()

file = client.files.create(
    file=open("draconomicon.pdf", "rb"),
    purpose="user_data"
)

response = client.responses.create(
    model="gpt-4.1",
    input=[
        {
            "role": "user",
            "content": [
                {
                    "type": "input_file",
                    "file_id": file.id,
                },
                {
                    "type": "input_text",
                    "text": "What is the first dragon in the book?",
                },
            ]
        }
    ]
)

print(response.output_text)

Base64-encoded files#

You can send PDF file inputs as Base64-encoded inputs as well.

Base64 encode a file to use in a response

import base64
from openai import OpenAI
client = OpenAI()

with open("draconomicon.pdf", "rb") as f:
    data = f.read()

base64_string = base64.b64encode(data).decode("utf-8")

response = client.responses.create(
    model="gpt-4.1",
    input=[
        {
            "role": "user",
            "content": [
                {
                    "type": "input_file",
                    "filename": "draconomicon.pdf",
                    "file_data": f"data:application/pdf;base64,{base64_string}",
                },
                {
                    "type": "input_text",
                    "text": "What is the first dragon in the book?",
                },
            ],
        },
    ]
)

print(response.output_text)

Usage considerations#

Below are a few considerations to keep in mind while using PDF inputs.

Token usage

To help models understand PDF content, we put into the model’s context both extracted text and an image of each page—regardless of whether the page includes images. Before deploying your solution at scale, ensure you understand the pricing and token usage implications of using PDFs as input.

File size limitations

You can upload up to 100 pages and 32MB of total content in a single request to the API, across multiple file inputs.

Supported models

Only models that support both text and image inputs, such as gpt-4o, gpt-4o-mini, or o1, can accept PDF files as input.

File upload purpose

You can upload these files to the Files API with any purpose, but we recommend using the user_data purpose for files you plan to use as model inputs.

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