Code beginner · 3 min read

How to use DALL-E API in python

Q: How to use DALL-E API in python

Use the OpenAI Python SDK's client.images.generate() method with your API key from os.environ to create images via the DALL-E API.

Direct answer

Use the OpenAI Python SDK's client.images.generate() method with your API key from os.environ to create images via the DALL-E API.

Setup

Install

bash

pip install openai

Env vars

OPENAI_API_KEY

Imports

python

import os
from openai import OpenAI

Examples

inGenerate a 512x512 image of a futuristic cityscape at sunset.

outURL to the generated 512x512 futuristic cityscape image.

inCreate a 1024x1024 image of a cute robot holding a flower.

outURL to the generated 1024x1024 image of a cute robot holding a flower.

inGenerate a 256x256 image of an astronaut riding a horse on Mars.

outURL to the generated 256x256 image of an astronaut riding a horse on Mars.

Integration steps

Install the OpenAI Python SDK and set your API key in the environment variable OPENAI_API_KEY.
Import os and OpenAI from the SDK.
Initialize the client with OpenAI(api_key=os.environ["OPENAI_API_KEY"]).
Call client.images.generate() with the prompt, model (e.g., "dall-e-3"), and image size.
Extract the image URL from the response's data[0].url field.
Use or display the returned image URL as needed.

Full code

python

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

response = client.images.generate(
    model="dall-e-3",
    prompt="A futuristic cityscape at sunset, digital art",
    size="1024x1024"
)

image_url = response.data[0].url
print("Generated image URL:", image_url)

output

Generated image URL: https://openai-generated-images.s3.amazonaws.com/abc123def456.png

API trace

Request

json

{"model": "dall-e-3", "prompt": "A futuristic cityscape at sunset, digital art", "size": "1024x1024"}

Response

json

{"created": 1680000000, "data": [{"url": "https://openai-generated-images.s3.amazonaws.com/abc123def456.png"}]}

Extractresponse.data[0].url

Variants

Streaming Image Generation ›

Use when the API supports streaming image generation to improve UX with progressive image loading.

python

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

# Note: DALL-E image generation currently does not support streaming responses in the SDK.
# This is a placeholder for future streaming support if added.

Async Image Generation ›

Use async version for concurrent image generation calls in an async Python application.

python

import os
import asyncio
from openai import OpenAI

async def generate_image():
    client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])
    response = await client.images.generate(
        model="dall-e-3",
        prompt="A cute robot holding a flower",
        size="512x512"
    )
    print("Generated image URL:", response.data[0].url)

asyncio.run(generate_image())

Alternative Model for Smaller Images ›

Use smaller image sizes to reduce latency and cost when high resolution is not required.

python

import os
from openai import OpenAI

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

response = client.images.generate(
    model="dall-e-3",
    prompt="An astronaut riding a horse on Mars",
    size="256x256"
)
print("Generated image URL:", response.data[0].url)

Performance

Latency~1-3 seconds per image generation depending on size

Cost~$0.02 per 1024x1024 image generated with DALL-E 3

Rate limitsDefault tier: 60 requests per minute, 1000 images per day

Keep prompts concise to reduce processing time.
Use smaller image sizes when high resolution is unnecessary.
Batch requests asynchronously to optimize throughput.

Approach	Latency	Cost/call	Best for
Standard sync call	~1-3s	~$0.02 per 1024x1024 image	Simple scripts and quick tests
Async calls	Concurrent ~1-3s per call	~$0.02 per 1024x1024 image	High throughput or web apps
Smaller image size (256x256)	~0.5-1s	~$0.005 per image	Low-cost, fast previews

✓

Quick tip

Always specify the image size explicitly in <code>client.images.generate()</code> to control output resolution and cost.

⚠

Common mistake

Forgetting to set the <code>OPENAI_API_KEY</code> environment variable or using deprecated SDK methods causes authentication or runtime errors.

Verified 2026-04 · dall-e-3

Verify ↗