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Black Forest Labs FLUX Kontext Max

The highest-quality tier of the FLUX Kontext family, delivering maximum prompt adherence and detail for context-aware image editing.
Flux Kontext Max is an image editing API that transforms a reference image based on a text prompt. Developed by Black Forest Labs, it is the highest-quality tier of the Kontext family, delivering maximum prompt adherence and fine detail for context-aware editing and generation. It accepts up to 4 reference images and produces high-quality images across 10 aspect ratios in PNG or JPEG format, suitable for professional creative workflows.

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Key capabilities

  • Context-aware editing: Uses a reference image and text prompt together for precise, prompt-driven transformations
  • Multi-image reference: Up to 4 reference image URLs (input_image, input_image_2, input_image_3, input_image_4) to guide the edit
  • Maximum prompt adherence: Highest-quality tier of the Kontext family for accurate detail and faithful edits
  • Prompt upsampling: Optional automatic prompt modification for more creative outputs
  • Fine-grained control: Adjustable guidance scale (1-10) and inference steps (1-100) for quality tuning
  • 10 aspect ratios: Square (1:1), widescreen (16:9), social story (9:16), classic (4:3), portrait, and more
  • Safety control: Adjustable moderation tolerance from 0 (most strict) to 6 (least strict)
  • Output formats: PNG (lossless) or JPEG (compressed)
  • Async processing: Webhook notifications or polling for task completion

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Use cases

  • Product photography: Edit and restyle product shots while preserving key elements
  • Marketing and advertising: Adapt existing campaign imagery to new concepts from text
  • Content creation: Transform illustrations and photos for blogs, social media, and websites
  • Design prototyping: Iterate on visual concepts using a reference image as a starting point
  • E-commerce: Generate consistent lifestyle and mockup variations at scale

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Edit images with Flux Kontext Max

Submit a reference image and a text prompt to the API. The service returns a task ID for async polling or webhook notification.

POST /v1/ai/text-to-image/flux-kontext-max

Create a new image editing task

GET /v1/ai/text-to-image/flux-kontext-max

List all Flux Kontext Max tasks with status

GET /v1/ai/text-to-image/flux-kontext-max/{task-id}

Get task status and results by ID

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Parameters

aspect_ratio accepts named string values only (for example widescreen_16_9), not numeric ratios like "16:9". Passing an unlisted value returns a 400 error.

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Aspect ratios

Generated image URLs are signed and expire quickly (around 10-15 minutes). Download or store the output promptly; do not treat the URL as a permanent link.

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Frequently Asked Questions

Flux Kontext Max is the highest-quality tier of Black Forest Labs’ FLUX Kontext family, built for context-aware image editing. You submit a reference image URL (input_image) and a text prompt via the API, receive a task ID immediately, then poll for results or receive a webhook notification when processing completes.
Both edit images using a reference image and text prompt. Flux Kontext Max is the highest-quality tier, offering maximum prompt adherence and detail. Flux Kontext Pro treats the reference image as optional guidance for broader text-to-image generation. Choose Flux Kontext Max when edit precision and detail are the priority.
Yes. Flux Kontext Max requires both a prompt and an input_image URL. The model uses the reference image as the basis for the edit and applies the transformation described in the prompt. You can supply up to 3 additional reference images with input_image_2, input_image_3, and input_image_4.
The seed influences generation and helps you steer toward similar results, but the Kontext provider does not guarantee identical output for an identical seed. Setting prompt_upsampling to true makes runs inherently non-reproducible, since the prompt is rewritten on each call.
The guidance parameter (1-10, default 3.0) controls how closely the model follows your prompt; higher values produce edits more faithful to the description. The steps parameter (1-100, default 50) controls quality: more steps produce finer detail but take longer to process.
Flux Kontext Max supports 10 aspect ratios, passed as named string values: square_1_1 (default), classic_4_3, traditional_3_4, widescreen_16_9, social_story_9_16, standard_3_2, portrait_2_3, horizontal_2_1, vertical_1_2, and social_post_4_5. Use the exact enum value, for example widescreen_16_9 for a 16:9 image; a numeric ratio like "16:9" returns a 400 error. Output is delivered as png (lossless) or jpeg (compressed).
See Rate Limits for current limits by subscription tier.
See Pricing for detailed rates and subscription options.

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Best practices

  • Reference image: Use a high-quality input_image with clear subjects for the most accurate edits
  • Prompt writing: Describe the exact edit or transformation you want, including lighting, atmosphere, and art style
  • Guidance tuning: Start with the default guidance (3.0) and increase for more literal prompt adherence
  • Production integration: Use webhooks instead of polling for scalable applications
  • Error handling: Implement retry logic with exponential backoff for 503 errors