You cannot fully stop downloads, because anything viewable in a browser can be saved. You can make it harder with:

• Disable right-click via JavaScript:

document.addEventListener('contextmenu', e => e.preventDefault());

• Overlay transparent layer over images
• Use watermarks
• Stream videos instead of direct files (HLS/DASH)
• Restrict drag-and-drop and direct links

Note: These only deter casual users. Screenshots or dev tools can still capture content.

For high-value media, combine watermarks, streaming, and low-res previews.