If you are a regular user of Microsoft PowerPoint for a long time, you must be aware of the PPT and PPTX file formats. Both these presentation file types have been part of Microsoft PowerPoint for quite some time now. PPT is the oldest PowerPoint file format that had been widely used for saving presentations to disc. It was replaced by the newer PPTX file format with the introduction of Office 2007 which is the default format for saving presentations ever since.

Since most users have upgraded to the newer version of PowerPoint, they may not have noticed the difference as the new files are saved to PPTX file formats by default. However, the fact is that both the PPT and PPTX file types are different as detailed below.


If you are wondering what are the apparent differences between PPT and PPTX file formats, you are at the right place. Following are the differences between PPT and PPTX file formats.

PPT and PPTX – The File Format Difference

The main difference between PPT and PPTX is that PPT file are saved to disc as binary files whereas PPTX files are saved in Office Open XML format.

PPT files save presentation content as binary collection of records and structures. These are arranged in binary streams as described in the PPT file format specifications.

In contrast, PPTX files are saved in the Office Open XML format where data is stored in compressed XML in ZIP format. The PPTX files can be opened and examined by renaming the .pptx extension of the file to .zip and extract it using commonly available extraction software such as WinZIP.

File Size Comparison of PPT and PPTX File Formats

Another difference between PPT and PPTX file formats is the file size. PPT files store content as binary streams that also contain related formatting and other styling information, leading to larger file sizes.

In comparison, PPTX files store the presentation in Open XML format which is stored to disc as compressed ZIP format. This reduces the overall file size twice as compared to the PPT file format, thus occupying less space on the disc.


PPTX is the modern file format that is where to stay. It is more flexible as compared to the PPT file format. More and more 3rd party applications can read and write to PPTX files due to its open-source XML-based implementation. PPTX files are also smaller in size as compared to PPT files and occupy less space on the disc. Therefore, PPTX is the obvious choice for creating PowerPoint presentations.