---
title: FLUX.1 Kontext [max] | Runware Docs
url: https://runware.ai/docs/models/bfl-flux-1-kontext-max
description: High fidelity FLUX.1 Kontext max for precise image edits
---
# FLUX.1 Kontext [max]

FLUX.1 Kontext [max] is a high quality text to image model for production workflows. It focuses on prompt accuracy, sharp local edits, and premium typography rendering. Use it for detailed visual design, branded visuals, and consistent character safe image generation.

- **ID**: `bfl:4@1`
- **Status**: live
- **Creator**: Black Forest Labs
- **Release Date**: July 11, 2025
- **Capabilities**: Image to Image, Image Editing

## Pricing

Each image generation costs $0.08 at 1024x1024.

- **1024x1024**: `$0.08`

## Compatibility & Validation

`width` and `height` must be used together.

---

The following dimension combinations are supported:

| Configuration | Dimensions |
| --- | --- |
| `1K (21:9)` | `1568x672` |
| `1K (16:9)` | `1392x752` |
| `1K (4:3)` | `1184x880` |
| `1K (3:2)` | `1248x832` |
| `1K (1:1)` | `1024x1024` |
| `1K (2:3)` | `832x1248` |
| `1K (3:4)` | `880x1184` |
| `1K (9:16)` | `752x1392` |
| `1K (9:21)` | `672x1568` |

## Request Parameters

**API Options**

Platform-level options for task execution and delivery.

### [taskType](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-tasktype)

- **Type**: `string`
- **Required**: true
- **Value**: `imageInference`

Identifier for the type of task being performed

### [taskUUID](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-taskuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID v4 identifier for tracking tasks and matching async responses. Must be unique per task.

### [outputType](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-outputtype)

- **Type**: `string`
- **Default**: `URL`

Image output type.

**Allowed values**: `URL` `base64Data` `dataURI`

### [outputFormat](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-outputformat)

- **Type**: `string`
- **Default**: `JPG`

Specifies the file format of the generated output. The available values depend on the task type and the specific model's capabilities.

- \`JPG\`: Best for photorealistic images with smaller file sizes (no transparency).
- \`PNG\`: Lossless compression, supports high quality and transparency (alpha channel).
- \`WEBP\`: Modern format providing superior compression and transparency support.

> [!NOTE]
> \*\*Transparency\*\*: If you are using features like background removal or LayerDiffuse that require transparency, you must select a format that supports an alpha channel (e.g., \`PNG\`, \`WEBP\`, \`TIFF\`). \`JPG\` does not support transparency.

**Allowed values**: `JPG` `PNG` `WEBP`

### [outputQuality](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-outputquality)

- **Type**: `integer`
- **Min**: `20`
- **Max**: `99`
- **Default**: `95`

Compression quality of the output. Higher values preserve quality but increase file size.

### [webhookURL](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-webhookurl)

- **Type**: `string`
- **Format**: `URI`

Specifies a webhook URL where JSON responses will be sent via HTTP POST when generation tasks complete. For batch requests with multiple results, each completed item triggers a separate webhook call as it becomes available.

**Learn more** (1 resource):

- [Webhooks](https://runware.ai/docs/platform/webhooks) (platform)

### [deliveryMethod](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-deliverymethod)

- **Type**: `string`
- **Default**: `sync`

Determines how the API delivers task results.

**Allowed values**:

- `sync` Returns complete results directly in the API response.
- `async` Returns an immediate acknowledgment with the task UUID. Poll for results using getResponse.

**Learn more** (1 resource):

- [Task Polling](https://runware.ai/docs/platform/task-polling) (platform)

### [uploadEndpoint](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-uploadendpoint)

- **Type**: `string`
- **Format**: `URI`

Specifies a URL where the generated content will be automatically uploaded using the HTTP PUT method. The raw binary data of the media file is sent directly as the request body. For secure uploads to cloud storage, use presigned URLs that include temporary authentication credentials.

**Common use cases:**

- **Cloud storage**: Upload directly to S3 buckets, Google Cloud Storage, or Azure Blob Storage using presigned URLs.
- **CDN integration**: Upload to content delivery networks for immediate distribution.

```text
// S3 presigned URL for secure upload
https://your-bucket.s3.amazonaws.com/generated/content.mp4?X-Amz-Signature=abc123&X-Amz-Expires=3600

// Google Cloud Storage presigned URL
https://storage.googleapis.com/your-bucket/content.jpg?X-Goog-Signature=xyz789

// Custom storage endpoint
https://storage.example.com/uploads/generated-image.jpg
```

The content data will be sent as the request body to the specified URL when generation is complete.

### [safety](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-safety)

- **Path**: `safety.checkContent`
- **Type**: `object (2 properties)`

Content safety checking configuration for image generation.

#### [checkContent](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-safety-checkcontent)

- **Path**: `safety.checkContent`
- **Type**: `boolean`
- **Default**: `false`

Enable or disable content safety checking. When enabled, defaults to `fast` mode.

#### [mode](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-safety-mode)

- **Path**: `safety.mode`
- **Type**: `string`
- **Default**: `none`

Safety checking mode for image generation.

**Allowed values**:

- `none` Disables checking.
- `fast` Performs a single check.

### [ttl](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-ttl)

- **Type**: `integer`
- **Min**: `60`

Time-to-live (TTL) in seconds for generated content. Only applies when `outputType` is `URL`.

### [includeCost](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-includecost)

- **Type**: `boolean`
- **Default**: `false`

Include task cost in the response.

### [numberResults](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-numberresults)

- **Type**: `integer`
- **Min**: `1`
- **Max**: `20`
- **Default**: `1`

Number of results to generate. Each result uses a different seed, producing variations of the same parameters.

**Inputs**

Input resources for the task (images, audio, etc). These must be nested inside the \`inputs\` object.

### [referenceImages](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-inputs-referenceimages)

- **Path**: `inputs.referenceImages`
- **Type**: `array of strings`

List of reference images (UUID, URL, Data URI, or Base64).

**Generation Parameters**

Core parameters for controlling the generated content.

### [model](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-model)

- **Type**: `string`
- **Required**: true
- **Value**: `bfl:4@1`

Identifier of the model to use for generation.

**Learn more** (3 resources):

- [Text To Image: Model Selection The Foundation Of Generation](https://runware.ai/docs/guides/text-to-image#model-selection-the-foundation-of-generation) (guide)
- [Image Inpainting: Model Specialized Inpainting Models](https://runware.ai/docs/guides/image-inpainting#model-specialized-inpainting-models) (guide)
- [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide)

### [positivePrompt](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-positiveprompt)

- **Type**: `string`
- **Required**: true
- **Min**: `2`
- **Max**: `3000`

Text prompt describing elements to include in the generated output.

**Learn more** (2 resources):

- [Text To Image: Prompts Guiding The Generation](https://runware.ai/docs/guides/text-to-image#prompts-guiding-the-generation) (guide)
- [Image Outpainting: Other Critical Parameters](https://runware.ai/docs/guides/image-outpainting#other-critical-parameters) (guide)

### [width](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-width)

- **Type**: `integer`
- **Required**: true
- **Paired with**: height

Width of the generated media in pixels.

**Learn more** (2 resources):

- [Image To Image: Dimensions Changing Aspect Ratio](https://runware.ai/docs/guides/image-to-image#dimensions-changing-aspect-ratio) (guide)
- [Image Outpainting: Dimensions Critical For Outpainting](https://runware.ai/docs/guides/image-outpainting#dimensions-critical-for-outpainting) (guide)

### [height](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-height)

- **Type**: `integer`
- **Required**: true
- **Paired with**: width

Height of the generated media in pixels.

**Learn more** (2 resources):

- [Image To Image: Dimensions Changing Aspect Ratio](https://runware.ai/docs/guides/image-to-image#dimensions-changing-aspect-ratio) (guide)
- [Image Outpainting: Dimensions Critical For Outpainting](https://runware.ai/docs/guides/image-outpainting#dimensions-critical-for-outpainting) (guide)

### [seed](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-seed)

- **Type**: `integer`
- **Min**: `0`
- **Max**: `9223372036854776000`

Random seed for reproducible generation. When not provided, a random seed is generated in the unsigned 32-bit range.

**Learn more** (1 resource):

- [Text To Image: Seed Controlling Randomness Deterministically](https://runware.ai/docs/guides/text-to-image#seed-controlling-randomness-deterministically) (guide)

**Provider Settings**

Parameters specific to this model provider. These must be nested inside the \`providerSettings.bfl\` object.

### [promptUpsampling](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-providersettings-bfl-promptupsampling)

- **Path**: `providerSettings.bfl.promptUpsampling`
- **Type**: `boolean`
- **Default**: `false`

Enable automatic enhancement and expansion of the input prompt.

### [safetyTolerance](https://runware.ai/docs/models/bfl-flux-1-kontext-max#request-providersettings-bfl-safetytolerance)

- **Path**: `providerSettings.bfl.safetyTolerance`
- **Type**: `integer`
- **Min**: `0`
- **Max**: `6`
- **Default**: `2`

Tolerance level for content moderation. Lower values are stricter; higher values are more permissive.

## Response Parameters

### [taskType](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-tasktype)

- **Type**: `string`
- **Required**: true
- **Value**: `imageInference`

Type of the task.

### [taskUUID](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-taskuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID of the task.

### [imageUUID](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-imageuuid)

- **Type**: `string`
- **Required**: true
- **Format**: `UUID v4`

UUID of the output image.

### [imageURL](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-imageurl)

- **Type**: `string`
- **Format**: `URI`

URL of the output image.

### [imageBase64Data](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-imagebase64data)

- **Type**: `string`

Base64-encoded image data.

### [imageDataURI](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-imagedatauri)

- **Type**: `string`
- **Format**: `URI`

Data URI of the output image.

### [seed](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-seed)

- **Type**: `integer`

The seed used for generation. If none was provided, shows the randomly generated seed.

### [NSFWContent](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-nsfwcontent)

- **Type**: `boolean`

Flag indicating if NSFW content was detected.

### [cost](https://runware.ai/docs/models/bfl-flux-1-kontext-max#response-cost)

- **Type**: `float`

Task cost in USD. Present when `includeCost` is set to `true` in the request.

## Examples

### Windblown Desert Cinema Marquee (Image to Image)

![Windblown Desert Cinema Marquee](https://assets.runware.ai/examples/bfl-flux-1-kontext-max/54b98eab-5d2c-45ac-bc85-aa92cf074f29.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "9d4d5b7b-3e05-4471-9c0f-4c9caa0091a5",
  "model": "bfl:4@1",
  "positivePrompt": "Reimagine the reference image as a meticulously restored mid-century desert cinema at blue hour, viewed from the front in a wide cinematic composition. Keep the building layout and perspective from the reference, but transform the scene into a polished contemporary editorial photograph. The marquee displays sharp, perfectly legible premium typography reading: STAR DUNE CINEMA and beneath it TONIGHT: SILENT COMET. Warm incandescent bulbs glow around the sign, casting elegant highlights across smooth stucco and brushed metal trim. Add a few parked vintage-inspired cars, drifting sand ribbons across the asphalt, tall dry grasses at the edges, glowing ticket window, subtle neon accents in amber and turquoise, distant mesas silhouetted against a dramatic violet-to-copper sky. Highly detailed textures, realistic reflections, clean composition, strong local edits, precise signage, commercial-grade finish.",
  "width": 1568,
  "height": 672,
  "seed": 78011,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/723d7e79-17bf-444a-9825-62d9b99e75d1.jpg"
    ]
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "9d4d5b7b-3e05-4471-9c0f-4c9caa0091a5",
  "imageUUID": "1a4463cd-a948-4e18-b326-7095b4471e05",
  "imageURL": "https://im.runware.ai/image/os/a20d05/ws/2/ii/1a4463cd-a948-4e18-b326-7095b4471e05.jpg",
  "seed": 78011,
  "cost": 0.08
}
```

---

### Wayfinding Mural Transit Concourse (Image Editing)

![Wayfinding Mural Transit Concourse](https://assets.runware.ai/examples/bfl-flux-1-kontext-max/0df8fa82-bf87-47c6-8bd1-35e1a3b3ae95.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "5e83175c-2c9f-456f-9f78-7a43a4b4bdd4",
  "model": "bfl:4@1",
  "positivePrompt": "Edit the provided transit concourse image into a premium branded wayfinding scene. Replace the blank wall with a large-scale graphic mural in deep cobalt, burnt orange, cream, and charcoal. Add crisp typographic signage integrated into the wall design with highly legible text that reads: 'NORTHBOUND PLATFORM', 'RIVER DISTRICT EXIT', 'LINE B', and 'TICKETS'. Use a refined sans serif typeface with flawless kerning, consistent hierarchy, and realistic placement following wall perspective. Include directional arrows, a simple network stripe motif, and subtle modular iconography. Preserve the existing architecture, floor reflections, lighting direction, camera angle, and overall realism. The result should feel like a high-end public space branding mockup, sharp, polished, contemporary, and production-ready.",
  "width": 1568,
  "height": 672,
  "seed": 32611,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/7b5f5209-e187-471f-ace0-66a082cfe4fc.jpg"
    ]
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "5e83175c-2c9f-456f-9f78-7a43a4b4bdd4",
  "imageUUID": "2bd7f59b-6607-4016-bdbd-104e53a94d55",
  "imageURL": "https://im.runware.ai/image/os/a12d13/ws/2/ii/2bd7f59b-6607-4016-bdbd-104e53a94d55.jpg",
  "seed": 32611,
  "cost": 0.08
}
```

---

### Futurist Museum Identity Wall (Image to Image)

![Futurist Museum Identity Wall](https://assets.runware.ai/examples/bfl-flux-1-kontext-max/ae8f0399-2762-4c90-877e-ab07f1bcfedb.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "9061f948-9ca3-4d47-b4ca-229b29b90364",
  "model": "bfl:4@1",
  "positivePrompt": "Transform the references into a high-end futuristic museum entrance interior, preserving the architectural layout from the first image while applying the visual identity cues from the second. Feature a sweeping feature wall with large, elegant typography reading AETHER HALL, directional signage, inset illuminated lettering, refined cobalt and ivory graphic bands, brushed aluminum accents, polished concrete, subtle reflections, sparse sculptural seating, and a premium cultural-institution aesthetic. Sharp text rendering, believable scale, clean composition, editorial architectural photography style, quiet sophisticated mood, highly detailed surfaces, no people.",
  "width": 1248,
  "height": 832,
  "seed": 47275,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/e832f395-35fe-4bee-b8e8-a74ddb0fe57e.jpg",
      "https://assets.runware.ai/assets/inputs/686273c3-d498-4396-ab48-99af21a1ff52.jpg"
    ]
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "9061f948-9ca3-4d47-b4ca-229b29b90364",
  "imageUUID": "7a29c647-2997-4d9f-8f18-15887eb9a322",
  "imageURL": "https://im.runware.ai/image/os/a17d13/ws/2/ii/7a29c647-2997-4d9f-8f18-15887eb9a322.jpg",
  "seed": 47275,
  "cost": 0.08
}
```

---

### Submerged Metro Signage Atrium (Image to Image)

![Submerged Metro Signage Atrium](https://assets.runware.ai/examples/bfl-flux-1-kontext-max/0f9f5788-6d25-451f-801b-d71fc30639b1.jpg)

**Request**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "20fda6c1-585e-4deb-ac1c-81bfc8acd15d",
  "model": "bfl:4@1",
  "positivePrompt": "Transform the reference transit atrium into a partially submerged futuristic evacuation hub inside a coastal megacity. Keep the architectural layout, escalators, gates, and sign placements aligned to the reference, but fill the lower level with clear shallow seawater and scattered floating emergency markers. Replace standard wayfinding with premium typography signage in bold sans-serif, featuring multilingual arrows, district names, platform codes, and emergency routes. Add suspended orange rescue rings, waterproof digital information panels, reflective puddles on upper walkways, weathered concrete, brushed steel, and pale cyan guidance strips embedded in the floor. Atmosphere tense but orderly, documentary realism, sharp local detail, clean text rendering, cinematic wide composition, natural color separation, high-end commercial visual design.",
  "width": 1392,
  "height": 752,
  "seed": 91494,
  "providerSettings": {
    "bfl": {
      "promptUpsampling": true,
      "safetyTolerance": 2
    }
  },
  "inputs": {
    "referenceImages": [
      "https://assets.runware.ai/assets/inputs/3d99a736-4975-436b-872c-a15cfbaae103.jpg"
    ]
  }
}
```

**Response**:

```json
{
  "taskType": "imageInference",
  "taskUUID": "20fda6c1-585e-4deb-ac1c-81bfc8acd15d",
  "imageUUID": "187382dc-df3c-44e1-b5b3-f3f027acf4f8",
  "imageURL": "https://im.runware.ai/image/os/a15d18/ws/2/ii/187382dc-df3c-44e1-b5b3-f3f027acf4f8.jpg",
  "seed": 91494,
  "cost": 0.08
}
```