Generate Images with AI

provider-replicate/image-generation (State-of-the-Art Image Generation)

You can run this example with:

npx promptfoo@latest init --example provider-replicate/image-generation
cd provider-replicate/image-generation

This example demonstrates state-of-the-art image generation using Replicate's latest models, particularly the FLUX family from Black Forest Labs.

Features

This example tests:

• FLUX 1.1 Pro Ultra - The highest quality model supporting up to 4MP images
• FLUX 1.1 Pro Ultra (Raw Mode) - For authentic, photorealistic results
• FLUX Dev - Open-source version for commercial use
• FLUX Dev Realism - Specialized for photorealistic outputs
• Stable Diffusion XL - For comparison with previous generation

Environment Setup

1. Get a Replicate API token from https://replicate.com/account/api-tokens
2. Set the environment variable:

   export REPLICATE_API_TOKEN=r8_your_token_here
   

Running the Example

Full Test Suite (8 different image types across 5 models = 40 images)

promptfoo eval

Quick Test (2 images with the best model)

promptfoo eval --filter-providers flux-1.1-pro-ultra --max-concurrency 1

Test Specific Image Types

# Test only portraits
promptfoo eval --filter-tests "Photorealistic portrait"

# Test only landscapes and architecture
promptfoo eval --filter-tests "landscape|architecture"

Image Types Tested

1. Photorealistic Portrait - Professional headshots
2. Artistic Landscape - Traditional painting style
3. Architectural Visualization - Modern building photography
4. Product Photography - Commercial product shots
5. Abstract Art - Expressionist paintings
6. Science Fiction - Cyberpunk cityscapes
7. Food Photography - Culinary presentation
8. Wildlife Photography - Nature and animals

Model Comparison

Model	Best For	Speed	Cost	Resolution
FLUX 1.1 Pro Ultra	Highest quality	Fast	$0.06/image	Up to 4MP
FLUX 1.1 Pro Ultra (Raw)	Photorealism	Fast	$0.06/image	Up to 4MP
FLUX Dev	General use	Medium	~$0.02/image	1024x1024
FLUX Dev Realism	Photorealistic	Medium	~$0.028/image	1024x1024
SDXL	Artistic styles	Fast	~$0.01/image	1024x1024

Configuration Options

You can customize generation parameters:

providers:
  - id: replicate:image:black-forest-labs/flux-dev
    config:
      width: 1344 # Image width
      height: 768 # Image height
      num_outputs: 1 # Number of images to generate
      guidance: 3.5 # How closely to follow the prompt (1-20)
      num_inference_steps: 28 # Quality vs speed tradeoff
      output_format: 'png' # png, webp, or jpg
      seed: 42 # For reproducible results

Important: Image URL Expiration

:::warning
Replicate image URLs expire after approximately 24 hours. To preserve generated images, use the included save-images.js hook that automatically downloads all images during evaluation.
:::

Automatic Image Downloads

This example includes a save-images.js hook that automatically downloads all generated images to an images/ directory. To enable it:

# Add to any config file
extensions:
  - file://save-images.js:hook

Or run with the included configuration:

promptfoo eval -c promptfooconfig-with-download.yaml

Downloaded images will be saved as:

• images/flux-dev-red-apple-on-a-white-table-2025-07-28T12-30-45.png
• images/sdxl-portrait-of-elderly-man-2025-07-28T12-31-02.png

Tips

1. For best quality: Use FLUX 1.1 Pro Ultra
2. For photorealism: Use FLUX 1.1 Pro Ultra with raw: true
3. For commercial use with downloaded weights: Use FLUX Dev
4. For artistic styles: SDXL often performs better than FLUX
5. Always download images if you need them later - URLs expire!

Viewing Results

After running the evaluation:

1. Check the terminal for immediate results
2. Open the generated web UI for visual comparison
3. Images are displayed inline with markdown formatting

Cost Estimation

Running the full test suite (40 images) costs approximately:

• FLUX 1.1 Pro Ultra: 16 images × $0.06 = $0.96
• FLUX Dev models: 16 images × ~$0.025 = $0.40
• SDXL: 8 images × $0.01 = $0.08
• Total: ~$1.44

Troubleshooting

1. Rate limits: Replicate has rate limits. Use --delay 1000 to add delays between requests or --max-concurrency 1 to run sequentially
2. Timeouts: Some models take 20-30 seconds on first run (cold start). The provider handles polling automatically
3. API errors: Ensure your Replicate API token is valid and has credits
4. Model not found: Check the model ID matches one from https://replicate.com/explore