How does AI image upscaling work?

AI upscaling uses a neural network (Real-ESRGAN) trained on millions of image pairs to predict and reconstruct high-frequency details like edges and textures that are missing in low-resolution images, producing dramatically sharper results than simple interpolation.

Is my image uploaded to a server?

No. The AI model runs entirely in your browser using WebAssembly (ONNX Runtime). Your images are never uploaded to any server.

AI Image Upscaler - Free Online Super Resolution

Upload Image

Drag & drop an image or click to browse

PNG, JPG, JPEG, WebP (max 10MB)

Settings

Scale Factor

Real-ESRGAN Neural Network · Runs in browser

What Is AI Image Upscaler?

AI Image Upscaler uses Real-ESRGAN, a state-of-the-art neural network for super-resolution, to enhance low-resolution images directly in your browser. Unlike simple interpolation methods, Real-ESRGAN reconstructs high-frequency details such as edges, textures, and fine patterns, producing dramatically sharper and cleaner results.

How Does It Work?

The tool uses Real-ESRGAN (Real-world Enhanced Super-Resolution GAN) running via ONNX Runtime Web. Your image is processed through the neural network in tiles, with each tile upscaled 4x natively. For 2x mode, the 4x output is downscaled to deliver the cleanest possible result. Everything happens locally in your browser — no data is sent to any server.

Key Features

2x and 4x upscaling with AI-powered super resolution
Real-time progress tracking with cancel support
Before/After comparison slider for quality assessment
Export as PNG, JPG, or WebP with quality control
Fully private — all processing happens in your browser
No file size limits beyond 10MB upload restriction

Supported Formats

Upload images in PNG, JPG, JPEG, or WebP format up to 10MB. Maximum input resolution is 4096×4096 pixels. Export your upscaled images in PNG (lossless), JPEG, or WebP format with adjustable quality.

Frequently Asked Questions

Is my image uploaded to a server?: No. The AI model runs entirely in your browser using ONNX Runtime Web. Your images never leave your device.
What is the difference between 2x and 4x?: 2x doubles the resolution (e.g., 512×512 → 1024×1024). 4x quadruples it (e.g., 512×512 → 2048×2048). The model natively upscales 4x, so 4x gives the full neural network output while 2x downscales from 4x for maximum quality.
Why is the processing slow?: Neural network inference in the browser is limited by your device's hardware. The model uses WebGL acceleration when available, falling back to WebAssembly. Larger images with 4x upscaling will naturally take more time.