by Black Forest LabsImage
FLUX.2 Klein 4B
The smallest, quickest FLUX for rapid drafts
- Up to 2K
- Up to 3 reference images
- 9 aspect ratios
From 2 credits per image≈ $0.02· Create Image
What it's like to use
FLUX.2 Klein 4B is Black Forest Labs' compact, open-licence image model. It creates and edits in one model, in nine aspect ratios up to 2048 pixels on the long side, with up to three reference photos, and it's built for speed.
Good for
- Fast drafts: many prompts, seeds and framings
- Mock-up posters and signs with neon light
- Swapping the background, light or weather behind a person
Real results from FLUX.2 Klein 4B
Every image and clip here was generated with FLUX.2 Klein 4B. Hit Recreate to open it in the studio with the same prompt and settings.
InputBring your own image
What FLUX.2 Klein 4B can do
Each mode opens in the studio with FLUX.2 Klein 4B already picked. The price shows before you generate.
How to prompt FLUX.2 Klein 4B
- Quote any words and say where they sit; try a few seeds, since a small model can misspell.
- Name colours as hex codes like #FF3EA5 next to the thing they colour. Expect the right hue rather than an exact match.
- In edits, state what stays the same (face, clothes, pose, framing) before describing the change.
Settings worth knowing
Everything else has a sensible default, so you can type a prompt and go.
resolution1K · 2K- Output size. Bigger sizes look sharper and cost more.
aspect_ratio1:1 · 16:9 · 9:16 · 4:3 +5- The shape of the frame: wide, square or tall.
image_urls≤ 3- Photos to edit or combine. Say in the prompt what each one adds.
seed0–2147483647- Reuse the same number to get a repeatable result.
How it compares
Same kind of job, different strengths and prices.
FLUX.2 Klein 9B is one size up, with steadier faces and hands.
Questions about FLUX.2 Klein 4B
How much does FLUX.2 Klein 4B cost?
On PopNow, the cheapest run of FLUX.2 Klein 4B costs 2 credits ($0.02) per image. Larger sizes cost more: 1K 2 · 2K 2. You pay with credits (1 credit = $0.01), the exact cost shows on the Generate button before you start, and failed generations are refunded automatically.
What can FLUX.2 Klein 4B do?
On PopNow, FLUX.2 Klein 4B works in these modes: Create Image and Edit Image. Pick one in the studio and add a prompt or an upload.
What sizes can FLUX.2 Klein 4B make?
FLUX.2 Klein 4B renders up to 2K in 9 aspect ratios, and edits with up to 3 reference images.
How should I write prompts for FLUX.2 Klein 4B?
Quote any words and say where they sit; try a few seeds, since a small model can misspell. Name colours as hex codes like #FF3EA5 next to the thing they colour. Expect the right hue rather than an exact match. In edits, state what stays the same (face, clothes, pose, framing) before describing the change.
FLUX.2 Klein 4B or FLUX.2 Klein 9B?
FLUX.2 Klein 9B is one size up, with steadier faces and hands.
Do I need to install anything to use FLUX.2 Klein 4B?
No. FLUX.2 Klein 4B runs in your browser on PopNow: write a prompt or add a file, choose the settings and download the result. Sign up and you can generate straight away.
Make something with FLUX.2 Klein 4B
Type an idea, pick your settings and see the price before you hit Generate.