Filepad

Filepad is a free browser tool for people who sell digital downloads. Drop in your files and it checks them against the upload limits of Etsy, Gumroad, Shopify and Payhip: file size, number of files, file types and file names, plus image pixel size and print dimensions. Everything runs locally in your browser, so files are never uploaded and there is no sign-up.

If a listing has too many files or a file is over Etsy's 20 MB limit, Filepad can split your files into ZIPs that each stay under 20 MB, named in order (part 1 of 3, part 2 of 3...).