A presentation looks right on your PC, but lines move or special characters disappear elsewhere. Font substitution is one possible cause. These steps cover PowerPoint for Microsoft 365 as a Windows desktop app; other versions and viewers may differ.
Clarify the source file and destination
Keep an unchanged backup of the PPTX and work on a separate sharing copy. Determine whether the recipient will only present or also edit text, and whether internet access is available. Note the fonts used, including bold/italic variants, and review representative slides with accented characters, symbols, tables and long headings.
Microsoft 365 cloud fonts can download in a suitable online Office environment. This does not guarantee offline presentation or compatibility with any other application. A successful test on your PC does not prove a font is embedded: it may simply be installed locally.
Embed fonts in the sharing copy
- Open the copy in PowerPoint and select File → Options → Save.
- Under Preserve fidelity when sharing this presentation, select the correct presentation and enable Embed fonts in the file.
- Choose Embed all characters if others will edit the text. Embed only the characters used in the presentation can reduce file size but limits later editing with additional characters.
- Confirm the options and save the copy. Read every message about fonts that cannot be saved; a checked box alone does not prove success.
Respect embedding limits
Not every font permits embedding. Windows Control Panel → Fonts can show embeddability for installed fonts. Preview/Print and Editable permissions are not equivalent. Follow the font licence; do not simply copy font files to the recipient.
If a required font cannot be embedded, use an appropriate alternative in the working copy that is available at the destination or permits embedding. Check every affected slide after replacement: different character widths change wrapping, tables and text-box sizes. Embedding can substantially increase file size.
Test at the actual destination
Open the saved copy on the intended system, preferably without the extra local font installation and offline if offline use is planned. Check slide view and Slide Show. For editable delivery, use another copy to test additional characters and saving again. If differences remain, delivery has not passed review.
If useful, also create a PDF reading copy via File → Export → Create PDF/XPS Document. Check every page and the export selection; do not accidentally include hidden slides or notes. PDF replaces neither editable PPTX nor animations and media playback, and it is not protection against later editing. Keep the original, checked PPTX and checked PDF separately.