FLUX.1 Kontext [pro]

AI Image Editing Model

Image $$ · 4¢

Black Forest Labs' 12-billion parameter multimodal flow transformer for in-context image generation and editing with character consistency, typography handling, and commercial-ready quality

2048 x 2048
Max Resolution
Supported Modes
Text to Image Image Edit
Active

Details

Model ID
flux.1-kontext-pro
Also known as: flux-kontext-pro
Family
flux.1-kontext
Max Input Images
1
Tags
image-generation text-to-image image-editing typography character-consistency
// Get Started

Ready to integrate?

Access flux.1-kontext-pro via our unified API.

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Available at 3 providers

Starting from

$0.040 /image via fal.ai, Fireworks AI, Replicate

Prices shown are in USD

See all providers

Providers & Pricing (4)

FLUX.1 Kontext [pro] is available from 4 providers, with per-image pricing starting at $0.04 through fal.ai.

fal.ai
Text to Image
fal/flux.1-kontext-pro
Provider Model ID: fal-ai/flux-pro/kontext/text-to-image
$0.040 /image
fal.ai
Image Edit
fal/flux.1-kontext-pro-edit
Provider Model ID: fal-ai/flux-pro/kontext
$0.040 /image
Fireworks AI
Text to Image Image Edit
fireworks/flux.1-kontext-pro
Provider Model ID: accounts/fireworks/models/flux-kontext-pro
$0.040 /image
Replicate
Text to Image Image Edit
replicate/flux.1-kontext-pro
Provider Model ID: black-forest-labs/flux-kontext-pro
$0.040 /image

flux-kontext-pro API OpenAI-compatible

Developers can integrate FLUX.1 Kontext [pro] into creative workflows via Lumenfall's OpenAI-compatible API to perform high-fidelity text-to-image generation and complex image editing using a 12-billion parameter flow transformer.

Base URL
https://api.lumenfall.ai/openai/v1
Model
flux.1-kontext-pro

Code Examples

Text to Image

/v1/images/generations
curl -X POST \
  https://api.lumenfall.ai/openai/v1/images/generations \
  -H "Authorization: Bearer $LUMENFALL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "flux.1-kontext-pro",
    "prompt": "",
    "size": "1024x1024"
  }'
# Response:
# { "created": 1234567890, "data": [{ "url": "https://...", "revised_prompt": "..." }] }

Image Edit

/v1/images/edits

Parameter Reference

Required Supported Not available

Core Parameters

Parameter Type Description Modes
prompt string Required. Text prompt for image generation
T2I Edit
seed integer Random seed for reproducibility
T2I Edit

Size & Layout

Parameter Type Description Modes
size string Image dimensions as WxH pixels (e.g. "1024x1024") or aspect ratio (e.g. "16:9")
WxH determines both shape and scale (aspect_ratio and resolution are ignored when size is provided). W:H format is equivalent to aspect_ratio.
T2I Edit
aspect_ratio string Aspect ratio of the output image (e.g. "16:9", "1:1")
Controls shape independently of scale. Use with resolution to control both. If size is also provided, size takes precedence. Any ratio is accepted and mapped to the nearest supported value.
T2I Edit
resolution string Output resolution tier (e.g. "1K", "4K")
auto 1K
Controls scale independently of shape. Higher tiers produce larger images and cost more. If size is also provided, size takes precedence for scale. Any tier is accepted and mapped to the nearest supported value.
T2I Edit
Output size aspect_ratio + resolution
Flexible
Auto "auto" Model chooses optimal dimensions
1K 13 sizes
Output size aspect_ratio + resolution
1183 × 887 "1183x887" or "4:3" + "1K"
916 × 1145 "916x1145" or "4:5" + "1K"
1145 × 916 "1145x916" or "5:4" + "1K"
1024 × 1024 "1024x1024" or "1:1" + "1K"
887 × 1182 "887x1182" or "3:4" + "1K"
724 × 1448 "724x1448" or "1:2" + "1K"
1448 × 724 "1448x724" or "2:1" + "1K"
836 × 1254 "836x1254" or "2:3" + "1K"
1254 × 836 "1254x836" or "3:2" + "1K"
768 × 1365 "768x1365" or "9:16" + "1K"
1365 × 768 "1365x768" or "16:9" + "1K"
670 × 1564 "670x1564" or "9:21" + "1K"
1563 × 670 "1563x670" or "21:9" + "1K"

How these parameters work

size

Exact pixel dimensions

"1920x1080"
aspect_ratio

Shape only, default scale

"16:9"
resolution

Scale tier, preserves shape

"1K"

Priority when combined

size aspect_ratio + resolution aspect_ratio resolution

size is most specific and always wins. aspect_ratio and resolution control shape and scale independently.

How matching works

Shape matching – we pick the closest supported ratio. Ask for 7:1 on a model with 4:1 and 8:1, you get 8:1.
Scale matching – providers use different tier formats: K tiers (0.5K 1K 2K 4K) or megapixel tiers (0.25 1). If the exact tier isn't available, you get the nearest one.
Dimension clamping – if a model has pixel limits, we clamp dimensions to fit and keep the aspect ratio intact.

Media Inputs

Parameter Type Description Modes
image file Required. Input image(s) to edit
Supports PNG, JPEG, WebP.
T2I Edit

Output & Format

Parameter Type Description Modes
response_format string How to return the image
url b64_json
Default: "url"
T2I Edit
output_format string Output image format
png jpeg gif webp avif
Gateway converts to requested format if provider doesn't support it natively.
T2I Edit
output_compression integer Compression level for lossy formats (JPEG, WebP, AVIF)
T2I Edit
n integer Number of images to generate
Default: 1
Gateway generates multiple images in parallel even if provider only supports 1.
T2I Edit

Additional Parameters

Parameter Type Description Modes
cfg_scale number Classifier-free guidance scale — higher values stick more closely to the prompt
T2I Edit
enhance_prompt fal boolean Whether to enhance the prompt for better results.
T2I Edit
prompt_upsampling replicate boolean Automatic prompt improvement
T2I Edit
safety_tolerance string The safety tolerance level for the generated image. 1 being the most strict and 5 being the most permissive.
1 2 3 4 5 6
T2I Edit
sync_mode fal boolean If `True`, the media will be returned as a data URI and the output data won't be available in the request history.
T2I Edit

Parameter Normalization

How we handle parameters across different providers

Not every provider speaks the same language. When you send a parameter, we handle it in one of four ways depending on what the model supports:

Behavior What happens Example
passthrough Sent as-is to the provider style, quality
renamed Same value, mapped to the field name the provider expects prompt
converted Transformed to the provider's native format size
emulated Works even if the provider has no concept of it n, response_format

Parameters we don't recognize pass straight through to the upstream API, so provider-specific options still work.

FLUX.1 Kontext [pro] FAQ

How much does FLUX.1 Kontext [pro] cost?

FLUX.1 Kontext [pro] starts at $0.04 per image through Lumenfall. Pricing varies by provider. Lumenfall does not add any markup to provider pricing.

How do I use FLUX.1 Kontext [pro] via API?

You can use FLUX.1 Kontext [pro] through Lumenfall's OpenAI-compatible API. Send requests to the unified endpoint with model ID "flux.1-kontext-pro". Code examples are available in Python, JavaScript, and cURL.

Which providers offer FLUX.1 Kontext [pro]?

FLUX.1 Kontext [pro] is available through fal.ai, Fireworks AI, and Replicate on Lumenfall. Lumenfall automatically routes requests to the best available provider.

What is the maximum resolution for FLUX.1 Kontext [pro]?

FLUX.1 Kontext [pro] supports images up to 2048x2048 resolution.

Overview

FLUX.1 Kontext [pro] is a 12-billion parameter multimodal flow transformer developed by Black Forest Labs, designed specifically for in-context image generation and editing. It extends the capabilities of the standard FLUX.1 architecture by allowing users to provide image inputs as references to maintain character consistency and stylization across frames. This model is engineered to balance high-fidelity visual output with complex instruction following, making it a professional-grade tool for coherent visual storytelling.

Strengths

  • Contextual Character Consistency: Excels at maintaining the identity, features, and attire of a subject across multiple generated images by utilizing image-to-image reference capabilities.
  • Typography and Text Rendering: Demonstrates high precision in rendering complex text strings and layouts, significantly reducing the “gibberish” artifacts common in earlier diffusion models.
  • In-Context Editing: Capable of performing precise edits on existing images while preserving the original composition, lighting, and style.
  • High Parameter Density: The 12B parameter architecture allows for a nuanced understanding of long, descriptive prompts, resulting in imagery that closely adheres to specific spatial and stylistic instructions.
  • Commercial-Ready Output: Produces 1MP+ resolution images with realistic textures, accurate human anatomy, and professional-grade lighting suitable for production environments.

Limitations

  • Computational Demand: Due to its 12-billion parameter count, inference is more resource-intensive and slower compared to “schnell” or “dev” variants of the FLUX family.
  • Prompt Sensitivity: To achieve the highest levels of character consistency, users often need to provide high-quality, clear reference images; low-resolution or cluttered references can degrade the output quality.
  • Higher Latency: Not optimized for real-time applications, as the multimodal flow transformer architecture prioritizes output depth over generation speed.

Technical Background

FLUX.1 Kontext [pro] is built on a multimodal flow transformer architecture, a design choice that facilitates better alignment between text prompts and visual data compared to standard U-Net architectures. It utilizes flow matching, a training technique that simplifies the generative process by learning a direct path between noise and the target image distribution. This 12B parameter model was trained to process both text tokens and image patches simultaneously, allowing the “context” (reference images) to directly influence the generation process at the latent level.

Best For

This model is ideal for storyboarding, character design for gaming or film, and brand-consistent marketing campaigns where a single character or product must appear in various environments. It is a strong choice for graphic design tasks that require embedded, legible text within a scene. FLUX.1 Kontext [pro] is available through Lumenfall’s unified API and playground, allowing developers to integrate high-consistency image generation into their workflows with a single integration.

Try FLUX.1 Kontext [pro] in Playground

Generate images with custom prompts — no API key needed.

Open Playground