Verified Specifications: FLUX 3 Klein vs FLUX.2 Klein
Both FLUX 3 Klein (full name FLUX 3 Image Klein) and FLUX.2 Klein are models from Black Forest Labs (BFL), the German company behind the FLUX model family. FLUX.2 Klein is the earlier Klein model from BFL. Because our verified sources as of October 16, 2026 do not cover the parameter counts, licensing terms, or pricing of FLUX.2 Klein, this page does not state specifications for the older model. Instead, we list the verified facts for FLUX 3 Klein so you can compare them directly against BFL’s FLUX.2 documentation.
| Feature | FLUX 3 Klein (Verified) | FLUX.2 Klein |
|---|---|---|
| Release Date | October 15, 2026 (HF repo created October 13, 2026 UTC) | Earlier generation (check BFL docs) |
| Model Size | 5.6B parameter image model + Qwen3-VL-4B text encoder | Not covered here (check BFL docs) |
| Max Resolution | Up to 4K | Not covered here (check BFL docs) |
| Capabilities | Text-to-image, instruction editing, up to 10 reference images, bounding-box layout control, text rendering | Not covered here (check BFL docs) |
| Minimum GPU | NVIDIA RTX 3090 (BFL docs); 8 GB VRAM for INT8 in ComfyUI | Not covered here (check BFL docs) |
| Open-Weight License | FLUX Kommunity License v1.0 (gated on Hugging Face) | Not covered here (check BFL docs) |
| BFL API Price | $0.008 (768 px), $0.009 (1K), $0.014 (2K), $0.036 (4K) | Not covered here (check BFL docs) |
For details on FLUX 3 Klein, see the BFL FLUX 3 Klein documentation and the Hugging Face repository.
Checklist: What to Compare Between Generations
When evaluating whether to start a new project on FLUX 3 Klein or stay on an existing FLUX.2 Klein setup, check the following four areas against BFL’s FLUX.2 documentation:
- Editing and Reference Capabilities: Verify whether your workflow needs features built into FLUX 3 Klein. The newer model generates images from text, edits images by instruction, combines up to 10 reference images, controls layout using bounding-box coordinates, and renders text inside images. It is also designed to be used with a prompt upsampler, as short prompts used directly give mediocre results.
- VRAM and Hardware Needs: Compare your local GPUs against the VRAM and hardware requirements for FLUX 3 Klein. BFL’s documentation lists an NVIDIA RTX 3090 as the minimum GPU. However, the ComfyUI FLUX 3 Klein tutorial states that its INT8 version runs on GPUs with 8 GB of VRAM. You can read more in our ComfyUI guide.
- License Terms: Review the license details for both models. FLUX 3 Klein uses the FLUX Kommunity License v1.0. According to the model card summary, non-commercial use is allowed, and individuals and companies with annual revenue under US$5 million may run the model in production and use generated images commercially (though this does not by itself allow commercial fine-tuning or redistribution). You must log in to Hugging Face and read the full
LICENSE.mdfile yourself before downloading the weights. - API Pricing: Check the BFL pricing documentation to see how API costs compare. For FLUX 3 Klein, BFL charges $0.008 at 768 px, $0.009 at 1K, $0.014 at 2K, and $0.036 at 4K per image, with image editing priced the same as generation. See our API overview for more on hosted options.
When to Pick Which Model
Based on the verified facts for FLUX 3 Klein, choose FLUX 3 Klein if you specifically need its documented capabilities: output up to 4K resolution, combining up to 10 reference images, bounding-box layout control, or instruction-based image editing at published per-image API prices. If you plan to run it on an 8 GB GPU, ComfyUI’s INT8 version is the documented route; for commercial use, read the license summary and the full license first.
Consider checking BFL’s FLUX.2 documentation for FLUX.2 Klein if you already have a working pipeline built around the earlier Klein model and do not need the specific features introduced in the October 2026 release.
If you want to test FLUX 3 Klein before reading through documentation or downloading weights, you can try it on Klein Studio, an unofficial site not affiliated with or endorsed by Black Forest Labs. Klein Studio runs FLUX 3 Klein through BFL’s API and offers 3 free 1K images per day per visitor with no sign-up, covering both text-to-image generation and editing one uploaded image.