The easiest way to convert a PowerPoint presentation is to import your file to Google Slides. To do this:
Go to the main Google Slides screen and select “Blank,” which will open an untitled presentation. Then click “File” and “Import Slides.”
Next, click “Upload.” You’ll see a space underneath where you can drag the PowerPoint file you want to import. You can alternatively click “Select a File From Your Device.” This allows you to browse different files on your computer.
Click each slide that you wish to use in the Google Slides platform. Alternatively, you can click “All” if you want to import the entire presentation.
Don’t forget to click the box at the bottom right-hand corner to maintain the original theme from your PowerPoint presentation.
Once all the appropriate slides are selected, click “Import Slides.”
This saves changes automatically to the cloud, and you should be able to view your PowerPoint presentation on Google Slides.