PPTX2HTML can convert MS-PPTX file to HTML by using pure javascript.
Support Chrome, Firefox, IE>=10 and Edge.
Here is the Online DEMO page.

0.2.7 (Beta Test)

• Text
  • Font size
  • Font family
  • Font style: blod, italic, underline
  • Color
  • Location
  • hyperlink
• Picture
  • Type: jpg/jpeg, png, gif
  • Location
• Graph
  • Bar chart
  • Line chart
  • Pie chart
  • Scatter chart
• Table
  • Location
  • Size
• Text block (convert to Div)
  • Align (Horizontal and Vertical)
  • Background color (single color)
  • Border (borderColor, borderWidth, borderType, strokeDasharray)
• Drawing (convert to SVG)
  • Simple block (rect, ellipse, roundRect)
  • Background color (single color)
  • Align (Horizontal and Vertical)
  • Border (borderColor, borderWidth, borderType, strokeDasharray)
• Group/Multi-level Group
  • Level (z-index)
• Theme/Layout

MIT