Flux 2 Klein 4b Text To Image
Playground
Try it on WavespeedAI!FLUX.2 [klein] 4B is a compact 4-billion-parameter text-to-image model that delivers fast generation with quality results. Ready-to-use REST inference API, best performance, no cold starts, affordable pricing.
Features
FLUX.2 Klein 4B Text-to-Image
FLUX.2 Klein 4B Text-to-Image is a lightweight yet capable text-to-image generation model. Describe your vision in text and get quality images with fast generation — the most affordable option in the FLUX.2 Klein family.
Why Choose This?
-
Fast and affordable 4B parameter model optimized for quick turnaround at the lowest cost in the Klein series.
-
Good prompt adherence Accurately interprets prompts to generate images that match your description.
-
Flexible sizing Custom width and height controls for any aspect ratio.
-
Prompt Enhancer Built-in tool to automatically improve your prompts for better results.
-
Best value Ideal for rapid prototyping, batch processing, and budget-conscious projects.
Parameters
| Parameter | Required | Description |
|---|---|---|
| prompt | Yes | Text description of the image you want to generate |
| width | No | Output width in pixels (default: 1024) |
| height | No | Output height in pixels (default: 1024) |
| seed | No | Random seed for reproducibility (-1 for random) |
How to Use
- Write your prompt — describe the image including subject, style, lighting, and mood.
- Set size — adjust width and height for your desired dimensions.
- Set seed — use -1 for random, or specify a number for reproducibility.
- Run — submit and download the generated image.
Pricing
| Item | Cost |
|---|---|
| Per image | $0.008 |
Simple flat-rate pricing regardless of image size.
Best Use Cases
- Rapid Prototyping — Quickly test ideas and concepts at minimal cost.
- Batch Generation — Lowest cost enables large-scale image production.
- Creative Exploration — Iterate on prompts without budget concerns.
- Drafts and Mockups — Generate initial visuals before refining with higher-tier models.
- Learning and Testing — Experiment with prompting techniques affordably.
Pro Tips
- Be specific in your prompts — include subject, style, lighting, colors, and atmosphere.
- Use the same seed to reproduce identical outputs or compare prompt variations.
- Start with 1024x1024 for balanced quality, adjust dimensions for specific needs.
- Need higher quality? Try FLUX.2 Klein 9B Text-to-Image.
- Need custom styles? Try FLUX.2 Klein 4B Text-to-Image LoRA.
Notes
- Most affordable option in the FLUX.2 Klein series.
- For best results, write detailed, descriptive prompts.
Related Models
- FLUX.2 Klein 4B Text-to-Image LoRA — With LoRA support for custom styles.
- FLUX.2 Klein 4B Edit — Image editing model.
- FLUX.2 Klein 9B Text-to-Image — Higher quality 9B version.
- FLUX.2 Pro — Flagship-quality text-to-image generation.
Authentication
For authentication details, please refer to the Authentication Guide.
API Endpoints
Submit Task & Query Result
# Submit the task
curl --location --request POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/flux-2-klein-4b/text-to-image" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
--data-raw '{
"size": "1024*1024",
"seed": -1,
"enable_sync_mode": false,
"enable_base64_output": false
}'
# Get the result
curl --location --request GET "https://api.wavespeed.ai/api/v3/predictions/${requestId}/result" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}"
Parameters
Task Submission Parameters
Request Parameters
| Parameter | Type | Required | Default | Range | Description |
|---|---|---|---|---|---|
| prompt | string | Yes | - | ||
| size | string | No | 1024*1024 | 256 ~ 1536 per dimension | |
| seed | integer | No | -1 | -1 ~ 2147483647 | |
| enable_sync_mode | boolean | No | false | - | If set to true, the function will wait for the result to be generated and uploaded before returning the response. It allows you to get the result directly in the response. This property is only available through the API. |
| enable_base64_output | boolean | No | false | - | If enabled, the output will be encoded into a BASE64 string instead of a URL. This property is only available through the API. |
Response Parameters
| Parameter | Type | Description |
|---|---|---|
| code | integer | HTTP status code (e.g., 200 for success) |
| message | string | Status message (e.g., “success”) |
| data.id | string | Unique identifier for the prediction, Task Id |
| data.model | string | Model ID used for the prediction |
| data.outputs | array | Array of URLs to the generated content (empty when status is not completed) |
| data.urls | object | Object containing related API endpoints |
| data.urls.get | string | URL to retrieve the prediction result |
| data.has_nsfw_contents | array | Array of boolean values indicating NSFW detection for each output |
| data.status | string | Status of the task: created, processing, completed, or failed |
| data.created_at | string | ISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”) |
| data.error | string | Error message (empty if no error occurred) |
| data.timings | object | Object containing timing details |
| data.timings.inference | integer | Inference time in milliseconds |
Result Request Parameters
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| id | string | Yes | - | Task ID |
Result Response Parameters
| Parameter | Type | Description |
|---|---|---|
| code | integer | HTTP status code (e.g., 200 for success) |
| message | string | Status message (e.g., “success”) |
| data | object | The prediction data object containing all details |
| data.id | string | Unique identifier for the prediction, the ID of the prediction to get |
| data.model | string | Model ID used for the prediction |
| data.outputs | string | Array of URLs to the generated content (empty when status is not completed). |
| data.urls | object | Object containing related API endpoints |
| data.urls.get | string | URL to retrieve the prediction result |
| data.status | string | Status of the task: created, processing, completed, or failed |
| data.created_at | string | ISO timestamp of when the request was created (e.g., “2023-04-01T12:34:56.789Z”) |
| data.error | string | Error message (empty if no error occurred) |
| data.timings | object | Object containing timing details |
| data.timings.inference | integer | Inference time in milliseconds |