Google Slides is heavily oriented towards cloud-based service which encourages its users to work and store nearly everything online. Sure, this is an idea that sells really well for many, but it’s difficult to beat the convenience of working with locally-stored software like Microsoft PowerPoint.
I have previously have explained how you can edit and present Google Slides while offline, check it out in case it sounds like a better approach for your case.
But if you still want to switch to the PowerPoint format (PPT/PPTX) from Google Slides, then follow these steps.
1. First, open the document on Google Slides.
2. Then, navigate to File > Download > Microsoft PowerPoint (.pptx).
3. The document has been downloaded to your device. Open it with PowerPoint.
4. By default, the file might be protected to read-only
5. And now the formerly Google Slides document has been converted into PowerPoint.
Please be aware that these two services don’t share the exact same features and compatibility. Further editing/corrections may be necessary after the conversion.
In case for whatever reason you want to switch back to Google Slides, the service allows you to upload a PowerPoint file to be used in the online-based format. But then again, compatibility issues may arise and adjustments could be inevitable.
So, perhaps it’s best to stick with one platform until you have finished presenting.