Why is the first run slower?

This tool needs a processing engine that is downloaded once and then cached: Transformers.js: model weights from the Hugging Face Hub on first use (tens of MB), then cached. Only the engine is downloaded. Your file never leaves your device.

Are my files uploaded?

No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.

Is it free? Are there limits or watermarks?

Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.

Does it work offline?

Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

Home / Image / Image Upscaler

Image Upscaler

Upscale images 2× to 4× with AI super-resolution.

Free, no uploads, no sign-up. Runs 100% in your browser.

How Image Upscaler works

Image Upscaler runs a Swin2SR super-resolution model with Transformers.js on WebGPU (or WASM as a fallback), processing the image tile by tile to enlarge it while restoring detail.

Input: JPG, PNG, WEBP, GIF, BMP.

How to use Image Upscaler

Drop one or more images onto Image Upscaler.
Tune the options. The before/after preview updates live.
Process the batch.
Download a single image, or everything as a ZIP.

Tips

Upscaling small images is fastest; very large images may take a while on CPU.
WebGPU-capable browsers are dramatically faster.

Image Upscaler FAQ

Why is the first run slower?: This tool needs a processing engine that is downloaded once and then cached: Transformers.js: model weights from the Hugging Face Hub on first use (tens of MB), then cached. Only the engine is downloaded. Your file never leaves your device.
Are my files uploaded?: No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.
Is it free? Are there limits or watermarks?: Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.
Does it work offline?: Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

Related tools

Background Remover: Remove image backgrounds with on-device AI. Replace with color or blur.
Image Resizer: Resize to exact pixels, percentages or social presets.
Video Upscaler: Upscale video to 1080p, 1440p or 4K with Lanczos + sharpening.
Image Compressor: Shrink images in bulk with quality and width controls and live savings.