Image extraction has an explicit PDF-object boundary
Merge accepts up to 20 PDFs; every other tool accepts one PDF. Each PDF is limited to 50 MiB, inputs are limited to 200 pages, generated downloads are limited to 100 MiB, and each run has a 60-second cancel/timeout boundary. Password-protected PDFs are rejected; these tools do not remove passwords. Inline images, masks, vectors, and undecodable objects may not be extracted; results are not a complete recovery of every visual in the PDF.