Canvas has two documented ceilings and the stricter one applies more often than people expect. The standard student guide says Canvas does not support file uploads larger than 5 GB. The Assignment Enhancements guide — the newer interface most institutions now run — says Canvas will not accept file uploads larger than 500 MB. Neither number is the real constraint for a photographed worksheet, but a third limit is: with Assignment Enhancements, multiple file selection is not available, and you can only select one file at a time for upload. So a five-page assignment photographed as five images is five separate picker trips, each one a chance to lose your place, and each one uploading the full weight of a phone camera file. There is one Canvas-specific detail worth knowing: attachments added as part of a graded assignment submission are copied to your user files but are not counted against your user quota, and once uploaded as a submission the file cannot be deleted. That means the storage cost lands on the institution, not you, yet the upload time still lands on you. Compressing first is what turns five slow uploads into five quick ones, and resizing is what keeps a 12MP phone capture from carrying nine megapixels Canvas will never display. Skwish resizes to a fixed long edge, compresses to a target size, converts to JPG or WebP, and batches everything into one ZIP when the assignment does allow multiple files.