Open a .pptx, tell the editor what to change - "retitle slide 2", "bold the step headers", "split the pricing slide into two" - review the live preview, then download the same deck with your edits applied. The file itself never leaves your browser; only the slides being edited are sent to the AI model.
or drop one anywhere on this page
Google Slides decks must be shared as "Anyone with the link". Edited decks download as .pptx - re-import to Google Slides with File > Open.