--- license: apache-2.0 base_model: black-forest-labs/FLUX.2-klein-4B base_model_relation: quantized pipeline_tag: text-to-image tags: - text-to-image - image-to-image - flux - flux2 - flux2-klein - comfyui - checkpoint - safetensors - aio - fp8 - nvfp4 language: - en ---

# 🚀 FLUX.2 [klein] 4B AIO ### Sub-second image generation — all-in-one, 4 – 6 steps, text-to-image and image editing, Apache-2.0

🚀 Quick start: download one of the four AIO files (FP8 is recommended), put it in ComfyUI/models/checkpoints/, load it with Load Checkpoint and generate with 4 – 6 steps and CFG 1.0 (this value is critical).

## ✨ At a glance | Property | Details | |:--|:--| | 🧩 **Type** | All-in-one checkpoint: UNet + Qwen3 text encoder + VAE in a single file | | 🏗️ **Base model** | [black-forest-labs/FLUX.2-klein-4B](https://huggingface.co/black-forest-labs/FLUX.2-klein-4B) (repackaged and converted) | | 📦 **Files** | FP8 (~7.7 GB) · FP16 (~15 GB) · BF16 (~15 GB) · NVFP4 (~5.7 GB, RTX 50xx only) | | 🎛️ **Settings** | 4 – 6 steps · CFG 1.0 (critical) · euler · simple or normal · 1024×1024 | | 🧰 **Workflow** | ComfyUI workflow `AIO-T2I-V1` in `workflows/` ([Civitai page](https://civitai.red/models/2327746)) | | 📜 **License** | Apache-2.0, free for personal and commercial use | ## ✨ What is FLUX.2 [klein] 4B AIO? FLUX.2 [klein] 4B AIO is an **All-in-One repackage** of Black Forest Labs' newest compact image generation model. This version includes **VAE, Text Encoder (Qwen3) and UNet** in a single file – just load and go! **"Klein"** means "small" in German – but this model is anything but limited. It delivers exceptional performance in Text-to-Image, Image Editing and Multi-Reference Generation, typically reserved for much larger models. --- ## 💎 Flux.2-4B-Distilled-AIO The only version on Civitai (4 precision files: FP8, FP16, BF16, NVFP4). All-in-one checkpoint: UNet + Qwen3 text encoder + VAE. Civitai: [Flux.2-4B-Distilled-AIO](https://civitai.red/models/2327389?modelVersionId=2618128) · Workflow: [🎨 AIO-T2I-V1](#🎨-aio-t2i-v1-workflow) · ComfyUI folder for all files: `models/checkpoints/` (Load Checkpoint) **📦 Available files (from the original description)** | Version | File | Precision | UNet | Text Encoder | VAE | Best for | | :--- | :--- | :---: | :---: | :---: | :---: | :--- | | 🟡 **FP8-AIO** (~7.7 GB) – *Recommended for most users* | [`flux-2-klein-4b-fp8-aio.safetensors`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-fp8-aio.safetensors) | FP8 | FP8 | FP8 | BF16 | Most users, quick tests, everyday use, lowest VRAM | | 🔵 **FP16-AIO** (~15 GB) – *For older GPUs* | [`flux-2-klein-4b-fp16-aio.safetensors`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-fp16-aio.safetensors) | FP16 | FP16 | FP16 | BF16 | Older GPUs (GTX 10xx, RTX 20xx), broadest compatibility | | 🟢 **BF16-AIO** (~15 GB) – *Maximum quality* | [`flux-2-klein-4b-bf16-aio.safetensors`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-bf16-aio.safetensors) | BF16 | BF16 | BF16 | BF16 | RTX 30xx/40xx/50xx, professional/commercial work | | 🔴 **NVFP4-AIO** (~5.7 GB) – *Maximum speed* ⚡ | [`flux-2-klein-4b-aio-nvfp4.safetensors`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-aio-nvfp4.safetensors) | NVFP4 | NVFP4 | FP4-mix | BF16 | **RTX 50xx only**, ultra-fast generations, Blackwell GPUs, low VRAM + extreme performance | **⚙️ Settings (from the original description):** 4–6 steps · CFG 1.0 (critical) · euler · simple (or normal) · 1024×1024 native · no negative prompt needed. *This version has no separate version description on Civitai.* ### 🖼️ Flux.2-4B-Distilled-AIO gallery All images below were posted to the **Flux.2-4B-Distilled-AIO** version on Civitai.

--- ## 🔄 Update – ⚡ Flux2-klein-4B-AIO-NVFP4 Fast generation with **Blackwell** in just a few seconds — even at **4 steps**, and scales nicely with more steps 🚀 ### 🕒 Performance ```text Prompt executed in 2.08 seconds ██████████████ 4 / 4 steps ~2.65 it/s ``` ✅ Extremely fast ✅ Stable ✅ Great quality for a distilled setup ### 🖼️ Example Generation **Prompt:** ```text Anime, powerful anime illustration with vibrant dark fantasy colors, one adult woman inspired by Jouryuu, tall imposing presence, long hair flowing dramatically, intense anime eyes, wearing an ornate battle-inspired dress referencing official visuals, heavy fabric and strong silhouette, standing confidently in a ruined temple environment, low-angle camera enhancing dominance, dramatic backlighting with red and violet tones, strong shadows, intense cel-shading, bold anime lineart, intimidating yet elegant presence, correct anatomy, no text, no watermark. ``` *(The Civitai description contains no embedded image for this prompt, so none is shown here.)* 💡 This setup is optimized for **speed**, making it ideal for quick iterations, testing ideas, or just having fun generating without long wait times. Have fun generating — and as always, thanks for all the feedback and support 🙌✨ ## 🎯 Key Features - ⚡ **4-6 Step Generation** – Sub-second inference on modern hardware - 📦 **All-in-One** – No separate VAE/Text Encoder download needed - 🎨 **Unified Architecture** – T2I, I2I Editing & Multi-Reference in one model - 📐 **1024×1024 native** – Optimized for this resolution - 💾 **Low VRAM** – Runs on consumer GPUs with ease - 📜 **Apache 2.0** – Fully open for commercial use! - 🔧 **LoRA-compatible** – Base version ideal for fine-tuning ## ⚙️ Recommended Settings - **Steps:** 4-6 (step-distilled, more steps ≠ better) - **CFG:** 1.0 ⚠️ CRITICAL! - **Sampler:** euler - **Scheduler:** simple (or "normal") - **Resolution:** 1024×1024 (native) ### ⚠️ CRITICAL: CFG Must Be 1.0! This is a **distilled model** optimized for CFG 1.0. Higher CFG values will produce worse results! ✅ CFG 1.0 = Correct ❌ CFG 3.5+ = Wrong, will look bad ### Additional Notes - **4 – 6 steps are optimal!** The model was step-distilled for fast inference - **No negative prompts needed** – works but not required - **Natural language prompts** – Just describe what you want to see ## 📥 Installation (ComfyUI) ### Quick Start 1. **Download** your preferred version (FP8/FP16/BF16) 2. **Place** in `ComfyUI/models/checkpoints/` 3. **Load** with the "Load Checkpoint" node 4. **Generate!** ### Folder Structure ```text ComfyUI/ └── models/ └── checkpoints/ └── flux-2-klein-4b-bf16-aio.safetensors (or fp16/fp8) ``` ## 🎨 Example Prompts **Photorealistic** ```text A professional photograph of a barista making latte art in a cozy coffee shop, morning light streaming through windows, shallow depth of field, shot on Sony A7III ``` **Digital Art** ```text A majestic dragon perched on a crystal mountain peak, aurora borealis in the background, fantasy digital painting, highly detailed scales, dramatic lighting ``` **Product Photography** ```text Minimalist product photo of a luxury perfume bottle on white marble, studio lighting, reflection, commercial photography ``` ## 💻 Capabilities ### ✅ What FLUX.2 [klein] 4B can do: - **Text-to-Image (T2I)** – High-quality image generation from text - **Image-to-Image (I2I)** – Single-reference editing - **Multi-Reference** – Multiple input images for controlled transformations - **Text Rendering** – Improved text rendering in images - **Photorealistic** – Professional photo quality - **Artistic Styles** – Diverse artistic styles ### ⚠️ Limitations: - Optimized for 1024×1024 (other resolutions possible but not optimal) - 4B model – less detail than larger models for complex scenes - Distilled version – less output diversity than base models ## 🔧 Technical Details - **Parameters:** 4 Billion - **Architecture:** Rectified Flow Transformer - **Text Encoder:** Qwen3-based - **Inference Steps:** 4-6 (step-distilled) - **Native Resolution:** 1024×1024 - **Precision:** BF16 / FP16 / FP8 (+ NVFP4 since v1.1) - **License:** Apache 2.0 ## 🆚 Comparison: 4B vs 9B | | FLUX.2 [klein] 4B | FLUX.2 [klein] 9B | | :--- | :---: | :---: | | Parameters | 4B | 9B | | VRAM | ~8-13 GB | ~29 GB | | GPU | RTX 3090/4070+ | RTX 4090+ | | Quality | Very Good | Excellent | | License | Apache 2.0 ✅ | Non-Commercial ❌ | | Commercial Use | Yes! | No | **→ 4B is perfect for:** Consumer hardware, commercial projects, fast iterations ## ❓ FAQ **Q: Do I need separate VAE/Text Encoder files?** No! AIO = All-in-One. Everything is included in a single file. **Q: Can I use this for commercial projects?** Yes! The 4B version is licensed under Apache 2.0. **Q: Why only 4-6 steps?** The model was step-distilled. More steps won't improve quality. **Q: Why must CFG be 1.0?** This is a distilled model optimized for CFG 1.0. Higher values will degrade output quality. **Q: FP8 vs BF16 – What's the difference?** FP8 is smaller and faster, BF16 has slightly better quality. For most applications FP8 is sufficient. **Q: Does this work with LoRAs?** Yes! Especially the Base version (non-distilled) is ideal for LoRA training. **Q: What's the difference from the 9B version?** 9B has better quality but is non-commercial only. 4B is Apache 2.0! ## 🐛 Troubleshooting **Images look "washed out" or oversaturated** - Check the CFG – it **must be 1.0** for the distilled model! - Use 4-6 steps **Poor text rendering** - Be more specific in your prompt - Use simple, short text - Place text requirements at the beginning of the prompt **Colors look off** - Try BF16 version instead of FP8 - Ensure your monitor is properly calibrated ## 🧩 Workflows ### 🎨 AIO-T2I-V1 workflow Civitai: [Flux.2-klein-Workflows – AIO-T2I-V1](https://civitai.red/models/2327746?modelVersionId=2618497) · Download: [`Flux.2-T2I-AIO.zip`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/workflows/Flux.2-T2I-AIO.zip) · [`Flux.2-T2I-AIO-workflow-v2.json`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/workflows/Flux.2-T2I-AIO-workflow-v2.json) ![AIO-T2I-V1 – node graph overview](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/workflows/workflow.png) **What it does:** Step 1 Load Checkpoint (AIO) → optional LoRA (`LoraLoader`, bypass toggle) → Step 2 prompt (`CLIPTextEncode`, negative via `ConditioningZeroOut`) → Step 3 size (`EmptyFlux2LatentImage`) → Step 4 generate (`KSampler`) → Step 5 optional upscale pass (`ImageScaleBy` 1.5× lanczos → `VAEEncode` → second `KSampler` at denoise 0.2) with before/after `Image Comparer`; images are saved with metadata. Built-in guide and resolution-preset notes. **⚙️ Settings (from the JSON):** base pass 6 steps · CFG 1 · euler · beta · 1024×1536; upscale pass 4 steps · CFG 1 · euler · simple · denoise 0.2. **📦 Models used** | File | Required? | Download | ComfyUI folder | |:--|:--|:--|:--| | Checkpoint (`CheckpointLoaderSimple`, preset `flux-2-klein-4b-bf16-aio.safetensors`) | required (one of the 4 AIO files) | [`flux-2-klein-4b-bf16-aio.safetensors`](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-bf16-aio.safetensors) · [FP16](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-fp16-aio.safetensors) · [FP8](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-fp8-aio.safetensors) · [NVFP4](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/flux-2-klein-4b-aio-nvfp4.safetensors) | `models/checkpoints/` | | LoRA (`LoraLoader`, placeholder `your_lora_here.safetensors`) | optional | any FLUX.2 [klein] 4B LoRA | `models/loras/` | **🔌 Custom nodes** | Custom node pack (external) | Nodes used in this workflow | Required? | |:--|:--|:--| | [rgthree-comfy](https://github.com/rgthree/rgthree-comfy) | `Fast Groups Bypasser`, `Image Comparer` | required | | [comfyui_image_metadata_extension](https://github.com/edelvarden/comfyui_image_metadata_extension) | `SaveImageWithMetaData` | required | Install with [ComfyUI-Manager](https://github.com/Comfy-Org/ComfyUI-Manager) (search the name) or `git clone` into `custom_nodes/`, then restart ComfyUI. Everything else is ComfyUI core.

🖼️ AIO-T2I-V1 · result image from the workflow page (1)

![AIO-T2I-V1 result](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO/resolve/main/images/workflows/t2i/result_1.jpg)

*The Civitai workflow version has no description text (only the files and images).* --- ## 🙏 Credits - **Original model:** Black Forest Labs - **Architecture:** Rectified Flow Transformer - **Text Encoder:** Qwen3 - **AIO repackage:** SeeSee ### Official Links - 🔗 [Black Forest Labs Blog](https://bfl.ai/blog/flux2-klein-towards-interactive-visual-intelligence) - 🔗 [GitHub Repository](https://github.com/black-forest-labs/flux2) - 🔗 [Hugging Face Collection](https://huggingface.co/collections/black-forest-labs/flux2) - 🔗 [Original 4B Model](https://huggingface.co/black-forest-labs/FLUX.2-klein-4B) ## 📜 License - This repository is a repackage (single-file AIO + precision conversions) of [black-forest-labs/FLUX.2-klein-4B](https://huggingface.co/black-forest-labs/FLUX.2-klein-4B), which is published under **Apache-2.0** – including its transformer, Qwen3 text encoder and VAE components as distributed in that repo. The text encoder is Qwen3-based ([Qwen/Qwen3-4B](https://huggingface.co/Qwen/Qwen3-4B), Apache-2.0). - Note: FLUX.2 [klein] **9B** and FLUX.2 [dev] use the non-commercial FLUX license; they are **not** part of this repository. ## 📋 Changelog **v1.1 – January 2026** ⚡ - 🆕 Added **NVFP4 AIO variant** (RTX 50xx / Blackwell) - ⚡ Ultra-fast inference (optimized for 4 steps) - 🧠 Extremely low VRAM usage - 🎯 Designed for maximum speed while keeping good image quality **v1.0 (January 2026)** - Initial Release - BF16, FP16 and FP8 versions - All-in-One with VAE + Text Encoder + UNet **License:** Apache 2.0 – Free for personal AND commercial use! 🎉 **The fastest open-source image generation model for ComfyUI!** ⚡ **Download and start creating!** 🚀 ---

🧭 More from SeeSee — all models

### 🧩 Checkpoints & AIO | Model | Hugging Face | Civitai | |:--|:--|:--| | AniSee | [SeeSee21/AniSee](https://huggingface.co/SeeSee21/AniSee) | [Model](https://civitai.red/models/2628747) · [Workflows](https://civitai.red/models/2630318) | | Z-Anime | [SeeSee21/Z-Anime](https://huggingface.co/SeeSee21/Z-Anime) | [Model](https://civitai.red/models/2483351) | | Z-Image-Turbo-AIO | [SeeSee21/Z-Image-Turbo-AIO](https://huggingface.co/SeeSee21/Z-Image-Turbo-AIO) | [Model](https://civitai.red/models/2173571) · [Workflow](https://civitai.red/models/2174008) | | ERNIE-AIO | [SeeSee21/ERNIE-AIO](https://huggingface.co/SeeSee21/ERNIE-AIO) | [Model](https://civitai.red/models/2551548) · [Workflow](https://civitai.red/models/2553748) | | Chroma-Anime-AIO | [SeeSee21/Chroma-Anime-AIO](https://huggingface.co/SeeSee21/Chroma-Anime-AIO) | [Model](https://civitai.red/models/2022057) · [Workflow](https://civitai.red/models/2027641) | | FLUX.2-klein-4B-AIO | [SeeSee21/FLUX.2-klein-4B-AIO](https://huggingface.co/SeeSee21/FLUX.2-klein-4B-AIO) | [Model](https://civitai.red/models/2327389) · [Workflow](https://civitai.red/models/2327746) | | QWEN-Anime | [SeeSee21/QWEN-Anime](https://huggingface.co/SeeSee21/QWEN-Anime) | [Model](https://civitai.red/models/2122738) · [Workflow](https://civitai.red/models/2135240) | | SeeMoss-Genesis | [SeeSee21/SeeMoss-Genesis](https://huggingface.co/SeeSee21/SeeMoss-Genesis) | [Model](https://civitai.red/models/3031179) · [Workflow](https://civitai.red/models/3031981) | | See-Krea2 | [SeeSee21/Krea-2-See-Krea2-Genesis](https://huggingface.co/SeeSee21/Krea-2-See-Krea2-Genesis) | [Model](https://civitai.red/models/2846618) · [Workflow](https://civitai.red/models/2936142) | ### 🎀 LoRAs | Model | Hugging Face | Civitai | |:--|:--|:--| | Illustrious Anime Collection | [SeeSee21/Illustrious-Anime-Collection](https://huggingface.co/SeeSee21/Illustrious-Anime-Collection) | [Model](https://civitai.red/models/1994924) | | Chroma Semi-Anime | [SeeSee21/chroma-Semi-Anime](https://huggingface.co/SeeSee21/chroma-Semi-Anime) | [Model](https://civitai.red/models/1992501) | | Kitsune Furry Girl | [SeeSee21/Kitsune-Furry-Girl-Z-Image](https://huggingface.co/SeeSee21/Kitsune-Furry-Girl-Z-Image) | [Model](https://civitai.red/models/2218232) | | Ayase Momo (Dandadan) | [SeeSee21/Ayase-Momo-Z-Image](https://huggingface.co/SeeSee21/Ayase-Momo-Z-Image) | [Model](https://civitai.red/models/2189797) |

[🧩 Checkpoints & AIO](https://huggingface.co/collections/SeeSee21/checkpoints-and-aio) · [🎀 LoRAs](https://huggingface.co/collections/SeeSee21/loras) · [🌐 Civitai](https://civitai.red/user/SeeSeeLP) · [▶️ YouTube](https://www.youtube.com/@SeeSee-AI) _{Made with ❤️ by SeeSee}