Images and Vision

Learn how to use vision capabilities to understand images.

Vision is the ability to use images as input prompts to a model, and generate responses based on the data inside those images. Find out which models are capable of vision on the models page. To generate images as output, see our specialized model for image generation.

You can provide images as input to generation requests either by providing a fully qualified URL to an image file, or providing an image as a Base64-encoded data URL.

Passing a URL

javascript

import OpenAI from "openai";

const openai = new OpenAI();

const response = await openai.responses.create({
    model: "gpt-4.1-mini",
    input: [{
        role: "user",
        content: [
            { type: "input_text", text: "what's in this image?" },
            {
                type: "input_image",
                image_url: "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg",
            },
        ],
    }],
});

console.log(response.output_text);

Image input requirements

Input images must meet the following requirements to be used in the API.

File types	Size limits	Other requirements
PNG (.png) JPEG (.jpeg and .jpg) WEBP (.webp) Non-animated GIF (.gif)	Up to 20MB per image Up to 500 individual images per request Up to 50 MB image bytes per request Low-resolution: 512px x 512px High-resolution: 768px (short side) x 2000px (long side)	No watermarks or logos No text No NSFW content Clear enough for a human to understand

Specify image input detail level

The detail parameter tells the model what level of detail to use when processing and understanding the image (low, high, or auto to let the model decide). If you skip the parameter, the model will use auto. Put it right after your image_url, like this:

{
    "type": "input_image",
    "image_url": "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg",
    "detail": "high",
}

You can save tokens and speed up responses by using "detail": "low". This lets the model process the image with a budget of 85 tokens. The model receives a low-resolution 512px x 512px version of the image. This is fine if your use case doesn’t require the model to see with high-resolution detail (for example, if you’re asking about the dominant shape or color in the image).

Or give the model more detail to generate its understanding by using "detail": "high". This lets the model see the low-resolution image (using 85 tokens) and then creates detailed crops using 170 tokens for each 512px x 512px tile.

Note that the above token budgets for image processing do not currently apply to the GPT-4o mini model, but the image processing cost is comparable to GPT-4o. For the most precise and up-to-date estimates for image processing, please use the image pricing calculator here

Provide multiple image inputs

The Responses API can take in and process multiple image inputs. The model processes each image and uses information from all images to answer the question.

javascript

import OpenAI from "openai";

const openai = new OpenAI();

const response = await openai.responses.create({
  model: "gpt-4.1-mini",
  input: [
    {
      role: "user",
      content: [
        { type: "input_text", text: "What are in these images? Is there any difference between them?" },
        {
          type: "input_image",
          image_url: "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg",
        },
        {
          type: "input_image",
          image_url: "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg",
        }
      ],
    },
  ]
});

console.log(response.output_text);

Here, the model is shown two copies of the same image. It can answer questions about both images or each image independently.

Limitations

While models with vision capabilities are powerful and can be used in many situations, it’s important to understand the limitations of these models. Here are some known limitations:

• Medical images: The model is not suitable for interpreting specialized medical images like CT scans and shouldn’t be used for medical advice.
• Non-English: The model may not perform optimally when handling images with text of non-Latin alphabets, such as Japanese or Korean.
• Small text: Enlarge text within the image to improve readability, but avoid cropping important details.
• Rotation: The model may misinterpret rotated or upside-down text and images.
• Visual elements: The model may struggle to understand graphs or text where colors or styles—like solid, dashed, or dotted lines—vary.
• Spatial reasoning: The model struggles with tasks requiring precise spatial localization, such as identifying chess positions.
• Accuracy: The model may generate incorrect descriptions or captions in certain scenarios.
• Image shape: The model struggles with panoramic and fisheye images.
• Metadata and resizing: The model doesn’t process original file names or metadata, and images are resized before analysis, affecting their original dimensions.
• Counting: The model may give approximate counts for objects in images.
• CAPTCHAS: For safety reasons, our system blocks the submission of CAPTCHAs.

Calculating costs

Image inputs are metered and charged in tokens, just as text inputs are. How images are converted to text token inputs varies based on the model.

GPT-4.1

Image inputs are metered and charged in tokens based on their dimensions. The token cost of an image is determined as follows:

• Calculate the number of 32px x 32px patches that are needed to fully cover the image
• If the number of patches exceeds 1536, we scale the image so that it can be covered by no more than 1536 patches.
• The token cost is the number of patches, capped at a maximum of 1536 tokens
• For gpt-4.1-mini, we multiply image tokens by 1.62 to get total tokens, and for gpt-4.1-nano, we multiply image tokens by 2.46 to get total tokens, that are then billed at normal text token rates.

Cost calculation examples

• A 1024 x 1024 image is 1024 tokens
  • Width is 1024, resulting in (1024 + 32 - 1) // 32 = 32 patches
  • Height is 1024, resulting in (1024 + 32 - 1) // 32 = 32 patches
  • Tokens calculated as 32 * 32 = 1024, below the cap of 1536
• A 1800 x 2400 image is 1452 tokens
  • Width is 1800, resulting in (1800 + 32 - 1) // 32 = 57 patches
  • Height is 2400, resulting in (2400 + 32 - 1) // 32 = 75 patches
  • We need 57 * 75 = 4275 patches to cover the full image. Since that exceeds 1536, we need to scale down the image while preserving the aspect ratio.
  • We can calculate the shrink factor as sqrt(token_budget × patch_size^2 / (width * height)). In our example, the shrink factor is sqrt(1536 * 32^2 / (1800 * 2400)) = 0.603.
  • Width is now 1086, resulting in 1086 / 32 = 33.94 patches
  • Height is now 1448, resulting in 1448 / 32 = 45.25 patches
  • We want to make sure the image fits in a whole number of patches. In this case we scale again by 33 / 33.94 = 0.97 to fit the width in 33 patches.
  • The final width is then 1086 * (33 / 33.94) = 1056) and the final height is 1448 * (33 / 33.94) = 1408
  • The image now requires 1056 / 32 = 33 patches to cover the width and 1408 / 32 = 44 patches to cover the height
  • The total number of tokens is the 33 * 44 = 1452, below the cap of 1536

GPT 4o and o-series

The token cost of an image is determined by two factors: size and detail.

Any image with "detail": "low" costs 85 tokens. To calculate the cost of an image with "detail": "high", we do the following:

• Scale to fit in a 2048px x 2048px square, maintaining original aspect ratio
• Scale so that the image’s shortest side is 768px long
• Count the number of 512px squares in the image—each square costs 170 tokens
• Add 85 tokens to the total

Cost calculation examples

• A 1024 x 1024 square image in "detail": "high" mode costs 765 tokens
  • 1024 is less than 2048, so there is no initial resize.
  • The shortest side is 1024, so we scale the image down to 768 x 768.
  • 4 512px square tiles are needed to represent the image, so the final token cost is 170 * 4 + 85 = 765.
• A 2048 x 4096 image in "detail": "high" mode costs 1105 tokens
  • We scale down the image to 1024 x 2048 to fit within the 2048 square.
  • The shortest side is 1024, so we further scale down to 768 x 1536.
  • 6 512px tiles are needed, so the final token cost is 170 * 6 + 85 = 1105.
• A 4096 x 8192 image in "detail": "low" most costs 85 tokens
  • Regardless of input size, low detail images are a fixed cost.

We process images at the token level, so each image we process counts towards your tokens per minute (TPM) limit.