Image size limits and accepted formats
About 6 megapixels of input on a computer and 2 on a phone; larger images are reduced to fit. PNG, JPEG, WebP, GIF, BMP, AVIF, HEIC and TIFF are accepted.
Output is limited by your device's memory: 4x multiplies the pixel count by 16. On a computer the input limit is about 6 megapixels (for example 3000 by 2000); on a phone about 2 megapixels. A larger image is reduced to fit before upscaling, and the page tells you when that happens.
Accepted inputs: PNG, JPEG, WebP, GIF, BMP, AVIF, HEIC and TIFF, up to 250 MB on a computer and 120 MB on a phone. The result is PNG, JPEG or WebP, at 2x or 4x.
For 8x, images up to 64 MP of output, or video, see Cloud HD.