FLUX.1 Kontext [dev]

Name: FLUX.1 Kontext [dev]
Brand: Black Forest Labs
SKU: flux-kontext-dev
Price: 0.03 USD
Availability: InStock

Image generationAvailable

by Black Forest Labsflux-kontext-dev

Open-weight version of FLUX.1 Kontext by Black Forest Labs. Instruction-based editing: pass an input image and a plain text edit ('change the jacket to red', 'remove the person on the left') and it applies the change while keeping the rest of the scene and identity consistent.

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Price: US$0.030/image
Aspect ratios: 1:1, 16:9, 9:16, 4:3, 3:4
Input → output: Text + Image → Image
Developer: Black Forest Labs
Updated: 23 September 2026

Playground

Try FLUX.1 Kontext [dev]

Input & output

US$0.030/image

Prompt

0 / 2,000

Edit instruction in plain language

Input Image

Image to edit

Aspect ratio(optional)

Advanced settings (3)

Output format(optional)

Guidance(optional)0–10

Steps(optional)1–50

⌘/Ctrl + Enter

Output

Your image appears here.

This run

US$0.03 · 3 credits

For accounts without a purchase: runs above 2 credits need a top-up.

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Usable 24 hours after sign-up, up to 5 runs per day and at most 2 credits per run. Other sign-in methods start without credits.

Examples

Real outputs from the public examples of this model on Replicate, with the prompt and settings that produced them. They were not generated live on this page.

Open full size
Input
Prompt
Change the car color to red, turn the headlights on
Settings
aspect_ratio

match_input_image
Open full size
Input
Prompt
change the letters to be gold
Settings
aspect_ratio

match_input_image
Open full size
Input
Prompt
remove the car
Settings
aspect_ratio

match_input_image

About FLUX.1 Kontext [dev]

TL;DRAs of 23 September 2026

FLUX.1 Kontext [dev] is a model by Black Forest Labs in the Image generation category. On Railwail, FLUX.1 Kontext [dev] costs US$0.030 per image. Supported aspect ratios: 1:1, 16:9, 9:16, 4:3 and 3:4.

Pricing

Prices in US dollars. Usage is charged from prepaid credits.

Per image	US$0.030 per image

1 credit = US$0.01

Cost calculator

Price calculator

Runs

Total

US$3.00

300 credits

Per run

US$0.03 · 3 credits

Fixed price per run, known before the run starts.

API

Call FLUX.1 Kontext [dev] with your Railwail API key. Use this model ID in the request:

flux-kontext-devAPI documentation Get an API key

No verified API example

The public API passes a different input format than this model needs. Use the playground above.

Specifications

Model ID: flux-kontext-dev
Developer: Black Forest Labs
Category: Image generation
Input: Text, Image
Output: Image
Output formats: WEBP, JPG, PNG
Aspect ratios: 1:1, 16:9, 9:16, 4:3, 3:4
Billing: Fixed price, known before the run
Catalog entry updated: 23 September 2026

Input parameters

Inputs and settings from the model's input schema. The example in the API section shows which of them the API accepts.

ParameterTypeDefaultAllowed values

promptrequired
Edit instruction in plain language
Type: Text
Default: –
Allowed values: up to 2,000 characters
input_imagerequired
Image to edit
Type: Text
Default: –
Allowed values: –
guidance
Type: Number
Default: 2.5
Allowed values: 0 to 10
aspect_ratio
Type: Choice
Default: match_input_image
Allowed values: match_input_image, 1:1, 16:9, 9:16, 4:3 or 3:4
output_format
Type: Choice
Default: webp
Allowed values: webp, jpg or png
num_inference_steps
Type: Integer
Default: 30
Allowed values: 1 to 50

Use cases

Related guides

AI Image Editing Models

All models in Image generation

Frequently asked questions

What is FLUX.1 Kontext [dev]?

FLUX.1 Kontext [dev] is a model by Black Forest Labs in the Image generation category.

How much does FLUX.1 Kontext [dev] cost on Railwail?

On Railwail, FLUX.1 Kontext [dev] costs US$0.030 per image. The price is known before the run starts. Usage is paid from prepaid credits; 1 credit equals US$0.01.

Which settings does FLUX.1 Kontext [dev] support?

According to its input schema, FLUX.1 Kontext [dev] knows these parameters: prompt (up to 2,000 characters), input_image, guidance (0 to 10), aspect_ratio (match_input_image, 1:1, 16:9, 9:16, 4:3 or 3:4), output_format (webp, jpg or png) and num_inference_steps (1 to 50).

How fast is FLUX.1 Kontext [dev]?

There are not enough measured runs of FLUX.1 Kontext [dev] on Railwail yet to state a run time. It depends on the input, the settings and the load at the provider.

Is FLUX.1 Kontext [dev] better than FLUX 1.1 Pro?

That depends on the task. FLUX.1 Kontext [dev] (Black Forest Labs) and FLUX 1.1 Pro (Black Forest Labs) are both models in the Image generation category. The comparison page shows their prices and specifications side by side.

Compare FLUX.1 Kontext [dev] and FLUX 1.1 Pro

Can FLUX.1 Kontext [dev] use an image as input?

Yes. Send the image in the input_image parameter.

Comparable models

All in this category

FLUX 1.1 ProBlack Forest Labs
Black Forest Labs' flagship text-to-image model. Faster generation than FLUX.1 Pro at higher prompt adherence, with strong photorealism and reliable spatial composition. Runs as a hosted Replicate model.
US$0.048/image
60 % more expensive per unit
Compare FLUX.1 Kontext [dev] vs. FLUX 1.1 Pro
Flux 1.1 Pro UltraBlack Forest Labs
FLUX 1.1 Pro in ultra mode. Up to 4 megapixel images with raw mode for photorealism.
US$0.072/image
140 % more expensive per unit
Compare FLUX.1 Kontext [dev] vs. Flux 1.1 Pro Ultra
Flux DevBlack Forest Labs
Black Forest Labs' development model. Fast, high-quality image generation with LoRA support.
US$0.0384/image
28 % more expensive per unit
Compare FLUX.1 Kontext [dev] vs. Flux Dev

All models through one API

One API key for every model on Railwail. Usage is charged from prepaid credits, 1 credit = US$0.01.

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