Stable Diffusion in your browser, now with fewer terminal windows

What it does

Sygil WebUI is a browser-based control panel for Stable Diffusion. It provides two interfaces—Streamlit as the current default and a legacy Gradio frontend—to handle text-to-image, image-to-image, and post-processing without command-line wrangling. The project bundles upscalers like GFPGAN and RealESRGAN, supports textual inversion, and claims to squeeze 512×512 generation into as little as 4 GB of VRAM when optimized mode is enabled.

The interesting bit

The Streamlit interface gets the active development: live previews during generation, a prompt matrix that combines prompts with a pipe character, and even a work-in-progress text-to-video pipeline. Meanwhile, the Gradio frontend has been relegated to maintenance-only mode, though it still holds exclusive rights to some tools like the GoBig and GoLatent upscalers and mask painting.

Key highlights

• Dual-interface architecture: Streamlit for new features, Gradio for legacy stability and specific upscalers.
• VRAM thriftiness: 512×512 generation reportedly works on 4 GB GPUs with optimized settings.
• Prompt engineering tools: weight tokens with decimals, negate concepts with ###, and batch-generate with sequential seeds.
• Post-processing buffet: GFPGAN for faces, RealESRGAN for resolution doubling, plus LSDR and latent upscalers.
• Textual inversion training and a Concepts Library for running custom embeddings directly in the UI.

Caveats

• The Gradio interface is no longer actively developed and receives only bug fixes, though some features like GoBig and mask painting remain locked to it.
• Text-to-video and Stable Horde integration are marked as works in progress.
• Several upscalers require manual model downloads into specific directories rather than shipping out-of-the-box.

Verdict

Worth a look if you want a feature-rich browser frontend for Stable Diffusion and can tolerate a split personality between its two UIs. Skip it if you need a single, fully integrated interface where every tool lives in one place.