Drop an image, get it at exactly 3840×2160 pixels (4K UHD, 16:9) — center cover-cropped, compressed to your target, GPS/EXIF stripped. Nothing is uploaded; it all runs in your browser.
3840×2160 is 4K UHD — exactly four Full-HD frames, same 16:9 shape. It's the native wallpaper size for 4K monitors and TVs, the canvas for digital-signage screens, and since YouTube's late-2025 thumbnail changes it's also the recommended thumbnail resolution when uploading from desktop (where the file cap is now a roomy 50 MB — mobile uploads still enforce the old 2 MB, which is why the 1280×720 page presets the works-everywhere combination). This page presets exact 4K pixels with a 4 MB budget.
The upscale warning earns its keep here: 3840×2160 is ~8.3 megapixels, and stretching a 1080p screenshot up to it produces a soft, slightly sad wallpaper. Modern phone photos (12 MP+) downscale into it beautifully; old web images don't. PixFit tells you when your source is smaller than the target instead of quietly stretching.
4 MB at 4K is solid JPEG quality for photographic wallpapers; raise the target if you see banding in skies or gradients — smooth gradients are what JPEG gives up first at this resolution. WebP holds gradients and hard edges better per byte if the destination accepts it. Smaller 16:9 siblings: 2560×1440 and 1920×1080.