Free AI Image Upscaler
Upscale any photo 2×, 3×, or 4× with AI — entirely in your browser. No signup, no upload, no watermark.
Need a fresh image to upscale? Generate one with AI.
First run downloads the model. Subsequent runs are cached and much faster.
Frequently asked questions
Is this AI upscaler really free?+
Yes. The AI model runs entirely in your browser using your device's CPU or GPU. No per-image cost, no signup, no watermark, no upload limit.
Does my photo get uploaded to a server?+
No. The image never leaves your device. Upscaling happens on-device with a small ESRGAN model that downloads once, then caches for future runs.
Why is the first upscale slow?+
On the first run your browser downloads the AI model and sets up TensorFlow. After that the model is cached and runs much faster — exact speed depends on your device and the chosen scale factor.
How big an image can I upscale?+
Anything up to ~1024×1024 at 4× works on most laptops. Above that, the AI runs in tiles to stay within memory limits, which takes longer but still works. Very small inputs (200–500 px on the long edge) give the cleanest results.
What's the difference between 2×, 3×, and 4×?+
2× doubles each side (4× the pixel count), 3× triples (9×), 4× quadruples (16×). Higher scales take longer and use more memory. For most cases 2× is fastest and looks great; pick 4× when you really need a much larger image.
What model is used?+
ESRGAN-Slim from UpscalerJS — a small, well-tuned super-resolution model that strikes a good balance between quality and speed in the browser.
Can I upscale AI-generated images?+
Yes — that's a great use. Generate an image with our AI generator and bring it here for a free 2×–4× upscale before you publish or print it.
What image formats are supported?+
Input: JPG, PNG, WebP. Output is a PNG to keep the upscale lossless.