SUPIR
Diffusion-based photorealistic upscaler.
Open Source 12–24 GB VRAM
- Min VRAM
- 12 GB
- GPU class
- Mid GPU
- Quant
- FP16
Actually FreeNo SignupWatermark-FreePlugin
Real-ESRGAN
The default OSS upscaler, still.
Open Source 2–6 GB VRAMRuns locally
Actually FreeNo SignupOpen SourceWatermark-FreeHobbyist-Friendly
Visit Real-ESRGANUpdated 2024-04-30 · Direct link
Hardware requirements
Runs locally · Entry GPU (6–8 GB)
Min VRAM
2 GB
Rec. VRAM
6 GB
Min RAM
4 GB
Rec. RAM
8 GB
Disk
2 GB
GPU class
Entry GPU
10.2+Apple Silicon ✓CPU-CapableQuant: FP16
Trivially small; runs on integrated GPUs and Apple Silicon.
Screenshot placeholder · Real-ESRGAN
What is Real-ESRGAN?
Real-ESRGAN from Tencent ARC Lab is the upscaler bundled into every diffusion UI for a reason: fast, lightweight, and decent on photos, anime, and game assets alike. Not state-of-the-art anymore (4x-UltraSharp, SUPIR, ESRGAN-NMKD variants beat it on specific content), but the universal baseline.
Pros & cons
Pros
- Bundled in A1111 / ComfyUI / Forge / InvokeAI by default
- Acceptable on photos AND illustration/anime via different weights
- Tiny model — runs CPU-only at acceptable speed
- Solid baseline you can always fall back to
Cons
- SUPIR / 4x-UltraSharp beat it on photographic detail
- Less specialized than newer purpose-trained upscalers
What's actually free?
BSD-3 from Tencent ARC Lab.
✓ Actually FreeNo SignupOpen SourceWatermark-Free
Alternatives
Topaz Video AI
GPU-accelerated upscaling, frame-interp, denoise.
Paid · from $299 4–12 GB VRAM
- Min VRAM
- 4 GB
- GPU class
- Mid GPU
- Quant
- —
Watermark-FreeHobbyist-Friendly