Everything you need to know about PPTX
PPTX (.pptx) is PowerPoint's presentation format since 2007 - the third member of the Office Open XML trio along with DOCX and XLSX. A PPTX file is a ZIP holding one XML file per slide, plus shared resources like themes, embedded media, and master layouts.
How it works under the hood
- Slide-per-XML. `ppt/slides/slide1.xml`, `slide2.xml`, etc. Each XML defines text frames, shape geometry, animations, and references to media.
- Slide masters and layouts. A layout defines slot positions; a master defines the overall theme. Slides inherit from a layout, which inherits from a master.
- DrawingML. Office Open XML's vector drawing language (similar to SVG) describes shapes, paths, gradients, 3D effects.
- Animations and transitions. Stored as XML in `<p:timing>` blocks. Complex animations have keyframe data, easing curves, and timing chains.
Where you'll actually use it
- Business presentations and pitch decks
- Conference talks (export to PDF for distribution)
- Sales decks with embedded videos and charts
- Educational lecture slides
How it compares to alternatives
PPTX vs Keynote: Keynote has better default design, PPTX has wider compatibility. PPTX vs Google Slides: Slides exports PPTX. PPTX vs PDF: PDF locks the layout for distribution; PPTX is the editable source.
Things that will trip you up
- Fonts not embedded by default - if your custom font isn't on the receiver's machine, layout breaks
- Embedded videos may not transfer correctly - PowerPoint's media linking is fragile
- Animations don't play in many third-party viewers (Google Slides supports a subset)
Test it yourself: Microsoft PowerPoint, Apple Keynote (imports/exports PPTX), Google Slides, LibreOffice Impress. Python: `python-pptx` for programmatic generation.