How to Use the Slideshare Downloader
Copy the presentation link
Open the deck on slideshare.net and copy the full address from your browser's address bar. On a phone, use the browser's Share → Copy option rather than a shortened share link.
https://www.slideshare.net/username/presentation-title
Paste it and press Fetch Slides
Go to the Free Slideshare homepage, paste the link and press Fetch Slides (or hit Enter). You'll see the title, a cover thumbnail and the slide count, followed by a slide-by-slide progress list.
Choose your format
Pick the file that suits what you'll do next:
Wait for the file, then open it
The button shows what it's doing while the file is prepared. Keep the page open; most decks are ready in a few seconds, very long ones in under a minute. The file is named after the presentation and saves to your usual downloads location.