Blackboard is the LMS where the limit you hit depends on which subsystem is reading the file. The student guide for Original Course View states a maximum file size limit of 300MB, quoted specifically to guarantee no data loss and good performance. But the administrator guide is blunt that the real ceiling is institutional: an administrator sets a general maximum upload size plus optional per-extension groups, and the guide's own example is a policy of 512MB for most files with a 25MB cap carved out for video. Then SafeAssign sits underneath all of that with a hard 25MB processing limit and a 100,000-word ceiling, and SafeAssign only reads formats it can convert to plain text — DOC, DOCX, DOCM, RTF, HTM, HTML, TXT, PDF, ODT, PPT, and ZIP of those. That last list matters more than the megabyte number for anyone submitting photographed work: an image-only PDF has no machine-readable text, so a similarity report either fails or flags nothing. The practical answer is to compress and resize the image set so a workbook or portfolio submission lands well under 25MB, and to submit scanned work as images or a text-bearing PDF rather than a fat image-only document. Blackboard also accepts a ZIP of multiple supported files, which is how a photographed page set becomes one clean submission. Skwish resizes, compresses to a target size, converts format and produces that ZIP in the browser.