I have reached the demo page: http://workhorsy.github.io/uncompress.js/examples/trivial/index.html

When the page loaded, button "Choose file" was active. But when I downloaded the page by Htttrack, opened it by chrome on android, the button was deactivated. I thought because the loading archive library cannot be loaded but cannot understand the loading mechanic of the code author. What can I do to made the loading successful or omit the loading steps?