A PowerPoint file is a digital document made up of slides, created with the presentation software developed by Microsoft. Each slide can contain text, images, videos, animations, and graphic elements. The format relies on two main extensions: .ppt (the old binary format) and .pptx (the compressed XML format, standard since several versions of the software).
Internal structure of a PowerPoint file: what the extension doesn’t reveal
The difference between .ppt and .pptx is not just one letter. The .ppt format, which appeared with the early versions of PowerPoint, stores data in a monolithic binary file. Any partial corruption of the file often renders the entire file unusable.
The .pptx format works differently. It is actually a ZIP archive containing several folders and XML files. Each slide, each image, each graphic theme is isolated in a separate file within this archive. Renaming a .pptx file to .zip allows you to explore this structure and manually extract an image or media without opening PowerPoint.
This architecture makes .pptx files lighter and more resistant to partial corruption. It also allows other software (LibreOffice Impress, Google Slides) to read them, since XML is an open standard. To better understand these mechanisms, you can discover the site Le Véridique which details the technical functioning of these files.
Other extensions exist for specific uses. The .pptm format retains macros (automated scripts in VBA), while .potx serves as a reusable template. The .ppsx, on the other hand, directly launches the slideshow upon opening, without displaying the editing interface.
PowerPoint file in a professional context: beyond simple presentation
In most companies, PowerPoint serves as a support for meetings, training sessions, and business proposals. The file becomes a shared working document, often modified by several successive users.
This is where the problems begin. The layout of a PowerPoint file depends on the fonts and versions installed on each workstation. A polished presentation on a Windows computer with Microsoft 365 may lose its alignment, fonts, or animations on a Mac equipped with an older version.
Three precautions can reduce this risk:
- Embed fonts in the file (option available in the save settings), which increases the document’s size but ensures correct text display.
- Export to PDF for final distribution, keeping the .pptx file as the editable working version.
- Use standard system fonts (Calibri, Arial) rather than downloaded fonts to limit incompatibilities between workstations.
The PDF format freezes the layout but removes all interactivity. The choice between sending a .pptx or a .pdf thus depends on the intended use by the recipient: passive consultation or modification.
Digital accessibility of PowerPoint files: a legal obligation in France
One aspect rarely addressed in guides on PowerPoint concerns French regulations regarding digital accessibility. Article 47 of law n° 2005-102, supplemented by decree n° 2019-768 and reinforced by ordinance n° 2023-859, mandates that digital content published by the relevant organizations comply with accessibility standards.
PowerPoint files are explicitly within the scope of these texts, as long as they are distributed online (integrated into a website, shared for download, or exported to PDF). A slideshow published without textual alternatives or proper structuring exposes the organization to a compliance failure.
Making a PowerPoint file accessible: technical points
PowerPoint includes an accessibility checker (Review tab). This tool flags slides without titles, images without alternative text, and insufficient contrasts. Here are the points to address as a priority:
- Add alternative text to each image, graphic, or non-decorative visual element, so that screen readers can convey them.
- Structure slides with predefined content areas (title, subtitle, body text) rather than free text boxes to ensure a logical reading order.
- Check color contrasts between text and background, avoiding poorly contrasted combinations (light gray on white, yellow on pale background).
- Give a unique title to each slide, even if it is not visually displayed, to allow navigation by structure.
Decree n° 2026-816 of August 24, 2026, adjusted the framework of the RGAA (General Reference for Accessibility Improvement) without creating new major obligations. Subject entities must publish an accessibility statement and a multi-year plan including their office documents.
Security and protection of a PowerPoint file
PowerPoint allows you to protect a file with a password at two distinct levels. The first prevents the document from being opened. The second allows reading but blocks any modifications. These two protections can be configured in the save options.
Password protection in PowerPoint is not robust encryption. For .pptx versions, the level of security remains acceptable for common corporate use, but does not replace a dedicated encryption tool for sensitive data.
The .pptm format, which allows VBA macros, presents an additional security risk. A .pptm file received by email may contain malicious code. Most recent Windows configurations block the execution of macros by default in downloaded files, but this protection depends on the user’s settings.
Renaming a .pptm file to .pptx does not remove the macros: PowerPoint will simply refuse to execute them. To clean a suspicious file, saving it in .pptx format from the interface remains the most reliable method.
The choice of file format affects both the compatibility, security, and accessibility of the final document. Keeping a .pptx as a working file, exporting to PDF for wide distribution, and reserving .pptm for projects requiring automation covers the vast majority of situations encountered in professional or educational environments.
