What is the PPT file format?
.ppt is a slideshow file format native to Microsoft PowerPoint. A .ppt file stores a multimedia presentation that can include slides, embedded images, videos, sound effects or audio tracks, and formatted text.
PPT files are frequently used for all kinds of presentations, from classroom lectures to corporate briefings. A presentation can be built from one of many predefined templates or created from scratch. Each slide is stored as a series of binary records inside an internal stream named PowerPoint Document, and the overall file follows the OLE2 Compound File Binary Format - the same container used by legacy .doc and .xls files.
The .ppt extension dates back to 1987 with the original release of PowerPoint for Mac, but the binary record layout in widespread use today - documented by Microsoft as [MS-PPT] - was established with PowerPoint 97 and remained the default format through PowerPoint 2003. Starting with PowerPoint 2007, .ppt was replaced as the default by .pptx, which is based on the Office Open XML standard and uses a ZIP archive container rather than OLE2. .ppt files are still opened by modern versions of PowerPoint, LibreOffice Impress, and Google Slides, but new presentations should be saved as .pptx.
.pps files use the same binary format as .ppt but open directly in slideshow mode rather than in the editor.
Security & safety
RISK: MEDIUMThe legacy binary .ppt can carry VBA macros, and binary Office formats have historically been a malware vector (boobytrapped records and macro payloads). Treat an unexpected .ppt the same as an old .doc: don't enable macros/content on a file you didn't request, and let modern PowerPoint open internet/email files in Protected View. Opening an unknown .ppt in Google Slides or LibreOffice Impress is generally safer because they render the slides without running PowerPoint VBA. Files renamed to look like .ppt can also hide other content - verify the source.
Format details
in a nutshellPrograms that open PPT files
Windows3 apps
Microsoft PowerPoint
Paid Double-click to open and edit (opens in Compatibility Mode). Press F5 to play; Save As .pptx to modernise. 
LibreOffice Impress
Open-source Free, full-featured. Double-click to open/edit the .ppt; File > Export As PDF, or play with F5. 
WPS Office Presentation
Freemium Free PowerPoint-like editor (formerly Kingsoft); familiar ribbon UI, opens and edits .ppt. 
macOS3 apps
Microsoft PowerPoint
Paid Double-click to open and edit the .ppt natively; Save As .pptx to upgrade it. 
Apple Keynote
Free Free on Mac; File > Open imports the PPT, and File > Export To > PowerPoint saves it back out. 
Linux1 app
LibreOffice Impress
Open-source Pre-installed on most distros; double-click to open and edit .ppt, export to PDF. 
Android3 apps
WPS Office
Freemium Popular free Android office app (replaces Kingsoft Office); opens and edits .ppt. 
Google Slides
Free Upload to Google Drive, open with Google Slides; download as PPTX or PDF afterwards.
PowerPoint for the web
Free Upload to OneDrive and open in PowerPoint online (free Microsoft account); highest fidelity online - it may prompt to convert to .pptx. Technical details
deep spec| Container format | OLE2 Compound File Binary Format (CFBF) - a FAT-like hierarchy of internal streams and storages |
| Encoding | Binary, little-endian byte order |
| MIME type | application/vnd.ms-powerpoint |
| File signature (magic bytes) | D0 CF 11 E0 A1 B1 1A E1 at offset 0 - the standard OLE2/CFBF header shared with legacy .doc and .xls |
| Primary internal stream | 'PowerPoint Document' stream holding binary slide records; companion streams include 'Pictures', 'Current User', and OLE summary information |
| Compression | None - records are stored uncompressed; embedded images keep their own encoding (JPEG, PNG, WMF, EMF) |
| Encryption | Optional RC4/CryptoAPI password protection; considered weak by modern cryptographic standards |
| Typical file size | 100 KB - 50 MB; grows rapidly with embedded images, audio, and video |
| Binary format versions | PowerPoint 97, 2000, XP, and 2003 share the same binary record layout - no format changes across those four releases |
| Format specification | Microsoft [MS-PPT] open specification, published via the Open Specifications programme at learn.microsoft.com |
| Superseded by | .pptx (Office Open XML, ISO/IEC 29500) since PowerPoint 2007, which switched to a ZIP+XML container |
| Related show-only format | .pps - identical binary format configured to open directly in slideshow mode, bypassing the editor view |
| Alternate MIME types | application/mspowerpoint, application/powerpoint, application/x-mspowerpoint (legacy variants still encountered on older servers) |
| Cross-platform support | Windows, macOS, Linux (via LibreOffice Impress), iOS, and Android |
| Released | 1997 (PowerPoint 97; the modern binary BIFF-style format that persisted through PowerPoint 2003) |
| Latest version | PowerPoint 2003 binary (.ppt) - last version where .ppt was the default; [MS-PPT] documents the format |
| Specification | learn.microsoft.com |
PPT conversions
Community Q&A
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