Keynote is arguably the best way to create presentations on your Mac or iOS device, but it's not necessarily the software most people have installed. If you work with Windows PCs then there's a good chance that Microsoft Powerpoint will be the go-to package. The problem is that when it comes to sharing Powerpoint creations they arrive in the .pptx format - one not often seen on macOS or iOS. Read next: How to edit PDFs on Mac for free
Stay your angst though, as Apple won't be overcome by the wrong letters at the end of a filename. So here are the easiest ways to edit a .pptx file on a Mac, iPad or iPhone.
For a more detailed look at how to work with Apple's presentation software you could also take a look at our How to use Keynote guide.
What is a .pptx file?
As you've probably guessed, a .pptx file is the proprietary file format used by Microsoft for its PowerPoint software.
This file type actually replaced the .ppt version in 2007, with the x indicating Microsoft's switch to an XML format which is far friendlier for other applications to open.
By contrast, .key is the standard file format for Keynote presentations.
How to edit a .pptx file on a Mac
Import .pptx files to Keynote
This one is pretty straightforward as every Mac since 2013 comes with Keynote preloaded. For those with older machines you'll be pleased to know that Apple has now made the entire iWork suite (Keynote, Pages, and Numbers), along with GarageBand, and iMovie free to download from the App Store.
With Keynote installed you just locate the .pptx file in Finder. Right click on it, then move the cursor onto Open with… and select Keynote.
You may see some warnings of fonts not being available. These will be proprietary ones, but Keynote will substitute them with a suitable replacement which you can always change if you prefer a different style.
Now you can edit the file as normal.
Export .pptx files from Keynote
Once you've finished editing your presentation you can export it in a .pptx format that your colleagues can use on PowerPoint.
Open the file in Keynote then go to File > Export To and select PowerPoint.
You'll see a box appear with Format: pptx. This is what you want so click Next, name the file then click Export.
This will create a file that you can now share without fear of getting a 'how do I open this?' email.
Use Microsoft Office
Of course the easiest way to interact with PowerPoint files on a Mac is to actually use PowerPoint itself. Microsoft offers the entire Office suite on macOS, and it's very good.
The current trend is to pay a monthly or yearly fee, the cost of which is £5.99 p/m or £59.99 p/a for a single user licence. Other tiers are also available if you want access to the software on more than one machine.
How to edit a .pptx file on iPad or iPhone
Importing to Keynote
Much like on the Mac, Apple has now made Keynote, Number, Pages, iMovie and GarageBand free on iOS. So if you don't already have Keynote installed, go to the App Store and download it.
To import your .pptx file you'll first need to ensure that the file is stored in your iCloud Drive. Once this is done open Keynote, tap Locations in the upper left corner, then select iCloud Drive.
You'll now be presented with the various folders on iCloud. Navigate to your file and tap it to import it to Keynote.
You might see a dialog box saying you need to change your iCloud settings to allow this. If this happens select Go to Settings and you'll be taken to the iCloud section. Here you just need to turn the Use iCloud option on.
Once that's done return to Keynote and repeat the above steps to open your presentation. Again you might see a warning saying that the presentation was created in an older version of the software and that some fonts will be different. Tap Open and you'll finally see your PowerPoint presentation.
Now you can edit the file, add new slides, effects, and what have you, just like any other Keynote presentation.
Exporting from Keynote
Any presentation you work on in Keynote will automatically be saved as a .key file. When you want to share this with PowerPoint users you'll first need to convert it to a .pptx file. This is achieved through the Send a Copy feature.
Tap the Presentations option in the top left corner to take you back to the main Keynote menu. Here you'll see all your files. In the upper right corner is the Share button (a square with a arrow pointing out of the top), tap this.
You'll be presented with three options - Collaborate with Others, Send a Copy, and Move to… - from which you should choose Send a Copy.
You'll now be asked to select which file you want to send. Tap your presentation and you'll see a pop-up box with the file types available. Tap PowerPoint and Keynote will convert your file.
Of course you'll want to send it to someone, so Keynote will open the Share menu where you can pick which method of communication you wish to use: Mail, Message, WebDav, and a number of others.
Use Microsoft Office Apps
Yep, just like on the Mac you can also use Microsoft's official PowerPoint app on iPhone and iPad. You can do basic editing on the free version and save to OneDrive, but for full features you'll need a paid Office365 account.
So there you go, various ways to share and edit PowerPoint files on your Mac, iPhone or iPad. For similar tips be sure to check out our How to edit .xlsx files on Mac, iPhone or iPad and How to open .docx files on Mac, iPhone, and iPad.