PPTX (PowerPoint)
Also known as: pptx file, PowerPoint presentation, slide deck format
PPTX is the default file format for Microsoft PowerPoint presentations since PowerPoint 2007. It is a ZIP package of XML and media, and because slide decks lean heavily on images and video, PPTX files are often the largest of the Office formats.
- Default PowerPoint format since PowerPoint 2007
- A ZIP package of XML plus embedded media
- Often the largest Office file because of images and video
Why PPTX files get large
A .pptx packages each slide’s text and layout as XML, but every photo, icon, embedded video, and audio clip is stored inside the same archive. A media-rich deck can easily reach tens or hundreds of megabytes.
High-resolution images placed at small sizes are the usual culprit — the slide shows them small, but the file keeps the full-size original unless you compress them.
Keeping decks small
Use PowerPoint’s built-in Compress Pictures option and link to video rather than embedding when possible. Removing unused slide masters and cropped-away image data also helps.
For distribution, /tools/powerpoint-to-pdf flattens a deck into a fixed-layout PDF — smaller to send and viewable anywhere without PowerPoint.