Flux 3 Image Klein setup vs Qwen Image 2.1 in ComfyUI

This tutorial sets up Flux 3 Image Klein in ComfyUI and compares its outputs with Qwen Image 2.1. The presenter uses shared prompts and seeds for image generation tests without LoRAs or multi-sampler refinements. These examples show results from the chosen settings, rather than a universal ranking.

Setup covers the dedicated ComfyUI repository's diffusion model, text encoder, VAE and example workflows. The presenter selects the distilled BF16 checkpoint, says the base model requires at least 50 sampling steps, and tests at 20 steps with CFG 3.5. The Qwen 3 VL4B text encoder and separate prompt upsampler are both required downloads; the upsampler goes in the text encoder folder. The speaker says system RAM offloading can help when VRAM is insufficient.

The comparisons cover short and long prompts, rain, moving subjects and difficult hands. The presenter prefers Qwen's textures and image structure in several examples, while finding anatomy errors in both models. Flux wins one hand comparison and earns praise for menu currency placement and scoreboard text.

Editing tests include a dress recolor that preserves patterns and jewelry. In the outfit transfer, Qwen retains more clothing detail, while Flux changes some colors and textures. Both place a banner in a lobby; the presenter prefers Flux's styling. Bounding-box editing is announced as a follow-up rather than demonstrated.