Quick Verdict
Use PPTX when…
Use PPTX for all new presentations — it is smaller, safer, and compatible with every modern app including Google Slides, Keynote, and LibreOffice.
Use PPT when…
Use PPT only if you must support PowerPoint 97–2003. Otherwise convert all old PPT files to PPTX immediately.
PPTX vs PPT: Feature Comparison
| Feature | PPTX | PPT |
|---|---|---|
| Introduced | 2007 (Office Open XML) | 1987 (Binary format) |
| File structure | ZIP archive of XML files | Binary (BIFF8) |
| File size | Smaller (XML compresses well) | Larger |
| Corruption risk | Lower (text-based, repairable) | Higher (binary, fragile) |
| Max slides | Effectively unlimited | Limited by memory |
| Animations / transitions | Full modern set | Limited older set |
| Themes & SmartArt | Full support | Limited |
| Google Slides support | Full import/export | Partial import |
| PowerPoint versions | 2007 and later | 97–2003 and all later |
When PPTX wins
- ✓Introduced: 2007 (Office Open XML)
- ✓File structure: ZIP archive of XML files
- ✓File size: Smaller (XML compresses well)
When PPT wins
- ✓Introduced: 1987 (Binary format)
- ✓File structure: Binary (BIFF8)
- ✓File size: Larger
Frequently asked questions
Can PowerPoint 2003 open PPTX files?
Not natively. Microsoft released a free Compatibility Pack that lets Office 2003 open .pptx, .docx, and .xlsx files with limitations. Advanced animations and themes from newer versions won't render correctly. For true compatibility, save a .ppt copy from a modern PowerPoint.
Does Google Slides support PPTX?
Yes — Google Slides imports and exports PPTX natively. You can open a PPTX file directly in Drive, edit it in Slides, and download it back as PPTX with most formatting intact. Complex animations may be simplified during round-trips.
Is PPTX better for large presentations?
Yes. PPTX uses ZIP compression, so text-heavy presentations are significantly smaller than equivalent PPT files. For media-heavy decks, the difference is less dramatic (images and video aren't re-compressed), but PPTX still handles large files more reliably due to its less error-prone structure.
How do I convert PPT to PPTX?
Open the PPT file in PowerPoint, then choose File → Save As and select 'PowerPoint Presentation (.pptx)'. In LibreOffice Impress: File → Save As → ODP or PPTX. Online converters also work for quick one-off conversions. After converting, verify all slides render correctly before deleting the original.
More comparisons
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