FLUX.1 Kontext [dev]

bfl/flux-2/kontext/dev

Flux 2 Kontext Dev by BFL - AI-powered image editing, style transfer, and transformation. Edit photos with natural language instructions, remove backgrounds, change styles, and enhance images effortlessly.

Base price
$0.03USD / run
Execution
async
Model type
image
Input fields
7
Production route

Try the model

Playground

Open playground
Input
The prompt to edit the image.

PNG, JPEG, WebP, or GIF · 20 MiB maximum

The URL of the image to edit. Max width: 14142px, Max height: 14142px, Timeout: 20s
120
The CFG (Classifier Free Guidance) scale is a measure of how close you want the model to stick to your prompt when looking for a related image to show you. Range: 1 to 20.
1050
The number of inference steps to perform. Range: 10 to 50.
Output format Allowed values: jpeg, png.
Determines how the output resolution is set for image editing. - `auto`: The model selects an optimal resolution from a predefined set that best matches the input image's aspect ratio. This is the recommended setting for most use cases as it's what the model was trained on. - `match_input`: The model will attempt to use the same resolution as the input image. The resolution will be adjusted to be compatible with the model's requirements (e.g. dimensions must be multiples of 16 and within supported limits). Apart from these, a few aspect ratios are also supported. Allowed values: auto, match_input, 1:1, 16:9, 21:9, 3:2, 2:3, 4:5, 5:4, 3:4, 4:3, 9:16, 9:21.
The same seed and the same prompt given to the same version of the model will output the same image every time.
OutputExample

Examples

Select an example to load its inputs and result into the playground.

Model card

Specifications

Pricing

Base price
$0.03 / run

Context & modalities

Input
Schema-defined
Output
image

Capabilities

Chat
Not supported
Vision
Not supported
Reasoning
Not supported
Structured output
Not supported
Function calling
Not supported
Audio input
Not supported

Access

Provider
BFL
Model ID
bfl/flux-2/kontext/dev
Execution
async
Base URL
https://api.sandbase.ai
API
Unified Run API
Endpoint
/v1/run

Human preference

Arena

Elo ratings from blind side-by-side votes, compared with other image and video models.

Rankings sourced from Artificial Analysis Arena

Leaderboard
Image Editing
Rank
#71 of 77
Elo
883 ±21
Gap to #1
−316

Image-editing arena: people pick the better of two edits of the same image and instruction, without seeing the model names.

  1. #66FLUX.1 Kontext [pro]Black Forest Labs916±19
  2. #67FIBO EditBria915±19
  3. #68SeedEdit 3.0ByteDance Seed901±20
  4. #69LongCat ImageMeituan897±20
  5. #70Qwen Image EditAlibabaOn SandBase889±20
  6. #71FLUX.1 Kontext [dev]Black Forest LabsThis model883±21
  7. #72HiDream-O1-Image-DevHiDream880±15
  8. #73GLM-ImageZ AI824±22
  9. #74BagelBytedance792±25
  10. #75OmniGen V2VectorSpaceLab785±23

API README

FLUX.1 Kontext [dev]

FLUX.1 Kontext [dev] edits a single image from an instruction: change objects, text, or style while keeping the rest consistent.

Fields

FieldTypeDefaultNotes
promptstring, required—Text instruction.
imageimage URL, required—Image to edit. JPEG, PNG, or WebP URL.
guidance_scalenumber 1–202.5How strictly to follow the prompt.
num_inference_stepsinteger 10–5028More steps add detail and time.
output_formatjpeg / pngjpegOutput file format.
resolution_modeauto / match_input / 1:1 / 16:9 / 21:9 / 3:2 / 2:3 / 4:5 / 5:4 / 3:4 / 4:3 / 9:16 / 9:21match_inputmatch_input keeps the input size; or choose a ratio.
seedintegerrandomFix it to compare prompt changes.

Billing

$0.025 per image.

RequestPrice
One image$0.025

Failed runs are not charged.

Prompting

  • State the change and what must stay the same.

Limits

  • One input image.

Also on SandBase

Related: bfl/flux-2/dev/edit (FLUX.2, multi-image).

Start building

Send your first request

OpenAI-compatible endpoint with unified authentication and usage tracking.

Production API
Unified Run API endpoint
https://api.sandbase.ai/v1/run
Model ID
bfl/flux-2/kontext/dev
# The quoted heredoc keeps Unicode and shell metacharacters unchanged.
result=$(curl --fail-with-body --silent \
  -X POST "https://api.sandbase.ai/v1/run" \
  -H "Authorization: Bearer $SANDBASE_API_KEY" \
  -H "Content-Type: application/json" \
  --data-binary @- <<'SANDBASE_JSON'
{
  "model": "bfl/flux-2/kontext/dev",
  "image": "https://static.sandbase.ai/examples/bfl/flux-2/kontext/dev/input_image_0.webp",
  "prompt": "Change the setting to a day time, add a lot of people walking the sidewalk while maintaining the same style of the painting",
  "output_format": "jpeg",
  "guidance_scale": 2.5,
  "resolution_mode": "match_input",
  "num_inference_steps": 28
}
SANDBASE_JSON
)
run_id=$(printf '%s' "$result" | jq -r .id)
for attempt in $(seq 1 120); do
  status=$(printf '%s' "$result" | jq -r .status)
  case "$status" in completed|failed|timeout) break ;; esac
  sleep 2
  result=$(curl --fail-with-body --silent \
    -H "Authorization: Bearer $SANDBASE_API_KEY" \
    "https://api.sandbase.ai/v1/run/$run_id")
done
status=$(printf '%s' "$result" | jq -r .status)
[ "$status" = completed ] || { echo "Generation ended: $status" >&2; exit 1; }
printf '%s\n' "$result"

Choose your model

Compare models

All image & video models
ModelTypeDefault priceReleased
BFLImage$0.03 / runMay 28, 2025
BFLImage$0.05 / runOct 1, 2026
BFLImage$0.05 / runOct 1, 2026
BFLImage$0.02 / runJan 15, 2026
BFLImage$0.02 / runJan 15, 2026
BFLImage$0.01 / runJan 15, 2026

Questions

FAQ

How do I call BFL FLUX.1 Kontext [dev] through SandBase?

Create a SandBase API key, then send requests with the model ID "bfl/flux-2/kontext/dev" to Unified Run API (/v1/run) at https://api.sandbase.ai. The request examples on this page show the exact payload.

Do I need a separate BFL account?

No. One SandBase API key and balance gives you access to BFL FLUX.1 Kontext [dev] and the other models in the catalog; you do not need to sign up with BFL separately.