Flux 2 Klein 9b Text To Image
Playground
Try it on WaveSpeedAI!FLUX.2 [klein] 9B is a high-quality text-to-image model with 9B parameters, offering enhanced realism and crisper text generation. Ready-to-use REST inference API, best performance, no cold starts, affordable pricing.
Features
FLUX.2 Klein 9B Text-to-Image is a powerful text-to-image generation model with 9B parameters. Describe your vision in text and get high-quality images with strong prompt adherence — delivering better detail and understanding than the 4B variant at an affordable price.
Why Choose This?
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Enhanced quality 9B parameter model delivers richer detail and better prompt understanding than the 4B variant.
-
Strong prompt adherence Accurately interprets detailed prompts to generate images that match your description.
-
Flexible sizing Custom width and height controls for any aspect ratio.
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Prompt Enhancer Built-in tool to automatically improve your prompts for better results.
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Balanced performance More capable than 4B while remaining fast and affordable.
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 | $0.01 |
Simple flat-rate pricing regardless of image size.
Best Use Cases
- High-Quality Generation — When 4B quality isn’t enough but full-size models are overkill.
- Production Work — Balanced quality and cost for professional content.
- Creative Projects — Detailed illustrations, concept art, and visual designs.
- Batch Generation — Affordable pricing enables large-scale image production.
- Rapid Prototyping — Fast generation for creative iteration.
Pro Tips
- Be specific in your prompts — include subject, style, lighting, colors, and atmosphere.
- Use the same seed to reproduce identical outputs or compare prompt variations.
- Start with 1024x1024 for balanced quality, adjust dimensions for specific needs.
- Need custom styles? Try FLUX.2 Klein 9B Text-to-Image LoRA.
Notes
- 9B model offers better detail than 4B at slightly higher cost.
- For best results, write detailed, descriptive prompts.
Related Models
- FLUX.2 Klein 9B Text-to-Image LoRA — With LoRA support for custom styles.
- FLUX.2 Klein 4B Text-to-Image — Lighter 4B version at lower cost.
- FLUX.2 Klein 9B Edit — Image editing model.
- FLUX.2 Pro — Flagship-quality text-to-image generation.
Authentication
For authentication details, please refer to the Authentication Guide.
API Endpoints
Submit Task & Query Result
set -euo pipefail
export WAVESPEED_API_KEY="your-api-key"
REQUEST_BODY=$(cat <<'JSON'
{
"prompt": "A cinematic ocean wave at sunrise, highly detailed",
"size": "1024*1024",
"seed": -1
}
JSON
)
# 1. Submit the prediction.
SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
-X POST "https://api.wavespeed.ai/api/v3/wavespeed-ai/flux-2-klein-9b/text-to-image" \
-H "Authorization: Bearer ${WAVESPEED_API_KEY}" \
-H "Content-Type: application/json" \
-d "${REQUEST_BODY}")
TASK=$(printf '%s' "${SUBMIT_RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
PREDICTION_ID=$(printf '%s' "${TASK}" | jq -r '.id // empty')
if [ -z "${PREDICTION_ID}" ]; then
printf 'Submission response did not contain a prediction id
' >&2
exit 1
fi
RESULT_URL=$(printf '%s' "${TASK}" | jq -r '.urls.get // empty')
if [ -z "${RESULT_URL}" ]; then RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"; fi
# 2. Poll until the prediction finishes.
while true; do
RESPONSE=$(curl --silent --show-error --fail-with-body \
"${RESULT_URL}" \
-H "Authorization: Bearer ${WAVESPEED_API_KEY}")
RESULT=$(printf '%s' "${RESPONSE}" | jq 'if type == "object" and has("data") then .data else . end')
STATUS=$(printf '%s' "${RESULT}" | jq -r '.status // empty')
case "${STATUS}" in
completed) printf '%s\n' "${RESULT}" | jq '.outputs'; break ;;
failed|cancelled|timeout) printf '%s\n' "${RESULT}" | jq . >&2; exit 1 ;;
created|processing) sleep 2 ;;
*) printf 'Unexpected status: %s
' "${STATUS}" >&2; exit 1 ;;
esac
doneParameters
Task Submission Parameters
Request Parameters
| Parameter | Type | Required | Default | Range | Description |
|---|---|---|---|---|---|
| prompt | string | Yes | - | - | |
| size | string | No | 1024*1024 | - | - |
| seed | integer | No | -1 | - | - |
| enable_sync_mode | boolean | No | false | - | If set to `true`, the request attempts to wait for the generated result and return outputs in the same response. If the result is not ready within the sync wait window, the API can return a timeout body while the task continues processing. This option is only available via the API and is supported only by some models. |
| enable_base64_output | boolean | No | false | - | If set to `true`, the prediction's `output` strings are returned as **naked base64** (no `data:<mime>;base64,` prefix). When `false` (default), outputs are returned as URLs pointing to our CDN. |
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 | Output values, usually URL strings; some models return text strings or structured result objects (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 |
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 |
| data.model | string | Model ID used for the prediction |
| data.outputs | array<string | object> | Array of generated outputs (empty when status is not completed). Items are usually URL strings, but may be text strings or structured result objects, depending on the model. |
| data.urls | object | Object containing related API endpoints |
| data.urls.get | string | URL to poll for the prediction result |
| data.status | string | Status: created, processing, completed, or failed |
| data.created_at | string | ISO timestamp of when the request was created |
| 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 |