In short
You do not need to pay for Microsoft 365 to make a presentation. Below are the free routes people use, what each is good at, and where each gets in the way. Features and free limits change, so check the tool's own page before relying on one.
PowerPoint for the web
Microsoft offers a browser version of PowerPoint with a free Microsoft account. It opens and saves .pptx files and covers the basics. Some advanced features of the desktop app are missing. Pick it if you must stay compatible with colleagues who use PowerPoint.
Google Slides
Free with a Google account, runs in the browser, and several people can edit at once. It exports to PDF and to .pptx. Pick it for shared decks and quick edits.
Keynote
Apple's presentation program is free on Apple devices and strong on animation and typography. Its files are less convenient to share with people on Windows, so export to PDF or PowerPoint for them.
LibreOffice Impress
Free and open source, installed on your computer, and it opens .pptx files. Pick it if you want no account and no cloud.
Canva and AI presentation tools
Canva has a free tier with presentation templates. AI tools such as Gamma generate a deck from a prompt, and their free tiers have limits that change, so read the current terms. Our notes: Canva vs carouselgen and Gamma vs carouselgen.
When the deck is for LinkedIn, not a meeting room
A landscape slide deck read on a phone is small. If the audience is on LinkedIn, make a portrait carousel and export it as a PDF. carouselgen does that from a prompt, and the free plan includes one new carousel a week.
Questions
Is there a free online PowerPoint?
Yes. PowerPoint for the web is free with a Microsoft account, and Google Slides is a free alternative that runs in the browser.
Can I open a .pptx file without PowerPoint?
Yes. Google Slides, Keynote and LibreOffice Impress can all open .pptx files, sometimes with small layout differences.
Make it as a carousel now
Paste your points or attach your deck. You get portrait slides and a PDF that fits a phone screen.
Try for free nowNo sign-up needed to try. The free plan exports with a small carouselgen.com mark.