How to use Image upscaler
- 1
Add an image
JPG, PNG, WebP or HEIC up to about 1.1 megapixels; larger pictures can be shrunk to fit in one click.
- 2
Choose scale and model
Pick 2× or 4×, then Best quality for the sharpest result or Fast for slower computers.
- 3
Upscale
Follow the tile-by-tile progress and estimated time left; cancel whenever you like.
- 4
Compare and save
Inspect details with the slider at 100% zoom, then download PNG, JPG or WebP.
Limits and Pro
Input images up to about 1.1 megapixels (for example 1280 × 860) and 25 MB, upscaled 2× or 4× with no watermark.
Inputs up to 4.2 megapixels at 2× and 2.1 megapixels at 4× — the most a browser tab holds comfortably in memory — and files over 25 MB. See Pro
About Image upscaler
The upscaler returns an image exactly two or four times wider and taller than the one you add, rebuilt by a Swin2SR super-resolution transformer rather than stretched with bicubic interpolation. A 640 × 480 photo becomes 1280 × 960 at 2× or 2560 × 1920 at 4×. The picture is processed in overlapping tiles and only the centre of each tile is kept, so no seams appear; transparency in PNG or WebP files survives because the alpha channel is resampled separately. Save the result as lossless PNG, or as JPG or WebP with adjustable quality; EXIF metadata is not carried over.
Three models are available: a lightweight 2× network that is quick on ordinary laptops, the classical 2× model for the crispest edges on clean images, and a real-world 4× model trained on photos with noise, blur and JPEG blocking, which tidies those artefacts while enlarging. Good candidates are small product photos, old scans, thumbnails needed for print, low-resolution screenshots and digital artwork.
Super-resolution predicts plausible detail. It cannot recover text that was unreadable, faces that were out of focus or motion blur, and it is no forensic enhancement tool. Video upscaling and enlargement beyond 4× in a single pass are not supported.
Privacy
Every tile is enhanced by an ONNX model running in Web Workers inside your browser, so your file never leaves your device and no server ever sees the pixels. The browser fetches the chosen model once (8 to 55 MB from Hugging Face) and keeps it cached, which also lets the upscaler work offline.
Features
Real super-resolution
Swin2SR transformers reconstruct edges and texture instead of interpolating pixels.
Seamless tiling
Overlapping tiles keep memory low on large images without visible joins.
Artefact clean-up
The real-world 4× model removes JPEG blocking and sensor noise while it enlarges.
AI upscaling compared with ordinary resizing
Bilinear and bicubic resizing only interpolate between existing pixels, so an enlarged picture looks soft and blocky. A super-resolution network has learned from millions of low- and high-resolution image pairs what fine structure usually looks like, and predicts plausible edges, textures and lines for the new pixels.
This tool uses three Apache-2.0 Swin2SR checkpoints: the classical ×2 model for clean images, a lightweight ×2 model for speed, and a real-world ×4 model trained on photos degraded by noise, blur and JPEG compression.