Aspect Ratios and Output Dimensions

Last updated: April 2, 2026

Aspect Ratios and Output Dimensions

FLUX.2

FLUX.2 gives you direct control over output dimensions. Set width and height to any values you need:

Parameter	Value
Minimum	256 × 256 pixels
Maximum	4 megapixels (e.g., 2048 × 2048)
Step size	Multiples of 16 pixels
Default	1024 × 1024
Aspect ratio	Any — no restrictions

Examples

Square: 1024 × 1024 (1MP)
Landscape 16:9: 1920 × 1088 (~2MP)
Portrait 9:16: 1088 × 1920 (~2MP)
Ultra-wide 21:9: 2048 × 880 (~1.8MP)
Max resolution: 2048 × 2048 (4MP)

Images over 4MP are automatically resized. We recommend staying at or below 2MP for optimal quality and speed.

Code example

import os
import requests

response = requests.post(
    "https://api.bfl.ai/v1/flux-2-pro",
    headers={
        "accept": "application/json",
        "x-key": os.environ.get("BFL_API_KEY"),
        "Content-Type": "application/json",
    },
    json={
        "prompt": "A panoramic mountain landscape at golden hour",
        "width": 1920,
        "height": 1088
    },
).json()
print(response)

FLUX.1 Kontext

Kontext outputs at a fixed ~1MP resolution. You can set aspect_ratio (e.g., "21:9") and the model adjusts dimensions to the nearest multiples of 32 pixels while staying at 1MP. Supported range: 3:7 to 7:3.