What is FLUX Kontext [pro]?

FLUX Kontext [pro] is Black Forest Labs' 12B-parameter in-context image editing model. It takes a source image and a text prompt, then applies targeted or full-scene edits while preserving subject identity — no masks or fine-tuning required.

How much does FLUX Kontext [pro] cost on Runflow?

$0.04 per image, flat pricing. Cold starts are not billed.

How does FLUX Kontext [pro] compare to FLUX Kontext [max]?

FLUX Kontext [pro] is faster and cheaper ($0.04 vs $0.08/image) for standard editing. [max] has stronger prompt adherence and better typography for demanding workflows. Both preserve subject identity.

Can FLUX Kontext do multi-turn editing?

Yes. You can apply successive edits that build on each other while maintaining visual coherence — each iteration preserves the results of previous transformations.

What input formats does FLUX Kontext [pro] accept?

JPG, JPEG, PNG, WebP, GIF, and AVIF. Pass the source image as a URL via the image_url parameter.

Can I use FLUX Kontext [pro] commercially?

Yes. FLUX Kontext [pro] is available under a commercial license for production applications, SaaS products, and client work.

Do I need to manage GPUs or infrastructure?

No. Runflow handles all GPU provisioning, scaling, and failover. You make an API call, you get back an image.

Black Forest Labs

FLUX Kontext [pro] API

FLUX Kontext [pro] — 12B-param in-context editor. Character consistency, style transfer, local edits. $0.04/image.

flux-pro-kontext12B paramsRectified Flow Transformer with reference conditioning

Updated March 2026·Early access

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Price

$0.04/image

Per image, flat pricing

Speed

Up to 8×

Faster than competing editing models

Cold Start

5–10s

Not billed, handled by Runflow

Parameters

12B

Multimodal Flow Transformer

FLUX Kontext model family by Black Forest Labs

In-context image editing and generation — multiple tiers on the same Runflow API.

FLUX Kontext [max]

Max

Premium — best prompt adherence and typography, $0.08/image

FLUX Kontext [pro]

This model

Standard — fast in-context editing with character consistency, $0.04/image

Benchmarked for your use case

Every model on Runflow is scored per vertical — not generic leaderboard numbers. Scores come from domain-expert evaluation on real production prompts.

Use Case	Assessment	Notes
Portrait	Strong	Identity-preserving scene changes and lighting edits
Fashion	Strong	Outfit and style transfer while maintaining model identity
Product	Strong	Context swaps that preserve product detail and branding
Creative	Strong	Multi-turn editing with coherent visual style across iterations

API Parameters

Full parameter reference for the flux-pro-kontext model endpoint.

Parameter	Type	Required	Description
prompt	string	required	Editing instruction describing the desired transformation.
image_url	string	required	URL of the source image to edit.
aspect_ratio	string	optional	Output aspect ratio. Options: square_hd, square, portrait_4_3, portrait_16_9, landscape_4_3, landscape_16_9.
num_images	integer	optional	Number of images to generate per request. Range: 1–4. Default: 1.
guidance_scale	float	optional	How closely the model follows the prompt. Range: 1–20. Default: 3.5.
output_format	string	optional	Output format. Options: "jpeg", "png". Default: "jpeg".
safety_tolerance	string	optional	Content moderation strictness. 1 = most strict, 6 = most permissive. Default: 2.
enhance_prompt	boolean	optional	Automatically enhance the prompt for better results. Default: false.
seed	integer	optional	Random seed for reproducible outputs.
sync_mode	boolean	optional	Return media as data URI without storing in request history. Default: false.

Technical Specifications

ArchitectureRectified Flow Transformer with reference conditioning

Parameters12 billion

ModeImage-to-image (in-context editing)

SpeedUp to 8× faster than state-of-the-art models

Guidance Scale3.5 (default) · 1–20 range

Max Batch Size4 images per request

Input FormatsJPG · JPEG · PNG · WebP · GIF · AVIF

Output FormatsJPEG · PNG

LicenseCommercial

Why run FLUX Kontext [pro] on the Runflow API

Flux AI models are available on many platforms. Here's what makes the Runflow image generation API different.

Character consistency without fine-tuning

Preserves subject identity, style, and brand elements across edits — no LoRA training or per-subject fine-tuning needed.

Up to 8× faster than competitors

Significantly faster inference than competing in-context editing models while maintaining high-quality results.

Local and global edits in one model

Handles everything from targeted region edits (change a shirt colour) to full scene transformations (move from studio to beach) — no separate models or masks needed.

Multi-turn editing

Apply successive refinements that maintain visual coherence — each edit builds on the previous one without degrading quality.

Sentinel quality scoring

Every output is scored by Runflow's Sentinel system for both generation quality and reference fidelity.

Explore other models

Same API, different strengths. Switch models with one parameter change.

Black Forest Labs

Frequently asked questions

Resources

API Documentation

Full endpoint reference, authentication, and response formats.

Sentinel Quality Evaluation

Automated quality gates for every image in your pipeline.

Start generating images with FLUX Kontext [pro]

Get API access in minutes. No GPU setup, no infrastructure to manage. Pair with Sentinel to control the quality of every AI-generated image you ship.

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