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black-forest-labs/flux-2-klein-9b-lora/text-to-imageFrom 3 credits per image· Create Image

FLUX.2 Klein 9B LoRA runs Black Forest Labs' step-distilled FLUX.2 [klein] 9B with up to three of your own LoRA files per request. Text to image comes in nine aspect ratios at 1k or 2k, and editing takes one to three reference images. Most of our test images came back in about ten seconds, at one flat price per image, with no review of prompts, weights or results.

Call it with the model name black-forest-labs/flux-2-klein-9b-lora/text-to-image on POST /jobs/createTask, from 3 credits per image ($0.03). New accounts get 30 free credits to try it in the Playground first.

  • Create Image
  • Edit Image
  • Up to 2K
  • Up to 3 reference images
  • 9 aspect ratios
  • Loads your own LoRA
by Black Forest LabsGet API keyFLUX.2 Klein 9B LoRA examples and prompts →

Introduction

FLUX.2 Klein 9B LoRA Text to image draws one image from a written prompt on Black Forest Labs' FLUX.2 [klein] 9B, the step-distilled 9B model, with up to three of your own LoRA files loaded from direct links. Choose one of nine aspect ratios at 1k or 2k and get a JPEG back, most often in about ten seconds of model time.

Choose a mode by starting material

What you haveMode
a written description and a LoRAFLUX.2 Klein 9B LoRA Text to image
one to three images to changeFLUX.2 Klein 9B LoRA Image editing

Key features

Your LoRAs, both klein 9B builds

LoRAs trained on the distilled klein 9B and on klein Base 9B both loaded here in our tests. FLUX.1 and klein 4B LoRAs, and files saved in diffusers PEFT format, ran without an error and changed nothing, so check the base model on the LoRA's card before you use it.

Fast enough to iterate

That makes it practical to try a LoRA at three strengths and a few seeds in one sitting, then keep the best frame.

Request parameters

ParameterRequiredDescription
aspect_ratioNoThe shape of the frame: wide, square or tall. 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3 · 21:9 · 9:21 · Default: 1:1
lorasNoLoad your own LoRA files to lock in a style or character. Default: []
promptYesDescribe the subject, setting, light and style in plain sentences. Put a LoRA trigger phrase first.
resolutionNoOutput size. Bigger sizes look sharper and cost more. 1k · 2k · Default: 1k
seedNoReuse the same number to get a repeatable result. ≥ 0 · ≤ 2147483647

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

OptionCredits per image≈ USD
Standard2.7$0.027

Each task is rounded up to whole credits, so one run at the lowest tier costs 3 credits per image ($0.03).

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

Run a hub LoRA as an API call

Paste a direct .safetensors link from a model hub, set the scale and write the prompt. There is nothing to train, host or keep warm, and up to three LoRAs stack in one request.

Prompt guide & pro tips

Trigger first, then sentences

Start with the LoRA's trigger phrase from its model card, then describe subject, clothing, place, light and lens in full sentences. The model follows long, specific prompts well, and there is no negative prompt, so say what you want rather than what to avoid.

Move the scale in small steps

Start at 0.8 to 1. In our tests 0.5 gave a faint version of a style and 4 broke the picture into blocks. Raise or lower by 0.2 and look at faces and hands first; they are the first things to distort.

Check that the LoRA is doing the work

Run the same prompt and seed with and without the file. Style LoRAs often refine a look the words already ask for, such as grain, grade or a pixel grid; LoRAs that teach new content change the picture outright. No visible change usually means the wrong base model.

Describe the clothes you want

Without a LoRA the model adds or keeps clothing on its own.

API quick start

Call the FLUX.2 Klein 9B LoRA API in three steps

  1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
  2. Send the request. POST /jobs/createTask with model black-forest-labs/flux-2-klein-9b-lora/text-to-image and an input object that follows the parameter table. The response returns a task ID straight away.
  3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "black-forest-labs/flux-2-klein-9b-lora/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "1k"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

FLUX.2 Klein 9B LoRA API questions

How much does the FLUX.2 Klein 9B LoRA API cost?

FLUX.2 Klein 9B LoRA starts at 3 credits ($0.03) per image with Create Image, its cheapest task. Credits are the same as on the website (1 credit = $0.01), new accounts get 30 free credits, and failed tasks are refunded.

What is the model name for FLUX.2 Klein 9B LoRA in the API?

Put black-forest-labs/flux-2-klein-9b-lora/text-to-image for Create Image; black-forest-labs/flux-2-klein-9b-lora/edit for Edit Image in the model field of POST /jobs/createTask.

Should I use this or FLUX.2 Klein Base 9B LoRA?

This is the step-distilled build: renders in about ten seconds and holds a polished, photographic look. Base is the undistilled build its makers recommend for training; it took two to five times longer in our tests and gave softer, more varied pictures. The same LoRAs load on both, so you can train on Base and run here.

My LoRA loaded but nothing changed. Why?

Three causes in our tests: the file was trained for another model (FLUX.1 or klein 4B), it was saved in diffusers PEFT format (keys ending in .default.weight), or it is a style LoRA whose look the prompt already asks for. None of these raise an error. Compare the same seed with and without the file.

What are the limits of the FLUX.2 Klein 9B LoRA API?

Resolutions: 1K · 2K; Aspect ratios: 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 +3; Prompt length (characters): 5,000. Requests outside these limits are rejected before anything is charged.

Can I try FLUX.2 Klein 9B LoRA without writing code?

Yes. The Playground runs FLUX.2 Klein 9B LoRA on your PopNow credits, needs no API key, and shows the matching code for every run.

All FLUX models

FLUX.2 Klein Base 9B LoRA is the undistilled build: two to five times slower, with softer, more varied pictures. The distilled build is quicker and more polished.

More about FLUX.2 Klein 9B LoRA