8 ways to open a .key file, matched to what it is
Methods 1 to 6 are for Keynote presentations, from easiest without a Mac to last resort. Methods 7 and 8 are for the other kinds of .key file.
Method 1: Publish Media Software
Easiest without a MacShows every slide of a Keynote file as a page, with no Mac or Apple Account. It doesn't play slide shows or save back to .key; adding content and PDF export are on a paid plan.
- 1
Go to publishmediasoftware.com and sign up free
- 2
Drag the .key file onto the upload area
- 3
Scroll through the slides as pages
- 4
Check the Import Report for swapped fonts
Method 2: Apple Keynote for Mac
Best for presentingThe app that made the file, so builds, transitions and video all work. Only runs on a Mac, and a deck saved in a newer Keynote may ask you to update the app first.
- 1
Install Keynote from the Mac App Store if it's missing
- 2
Double-click the .key file in Finder
- 3
Click Play to run the slide show
- 4
Use File › Export To for a PowerPoint or PDF copy
Method 3: Keynote for iPhone and iPad
On your iPhone or iPadApple's free mobile app opens .key attachments from Mail or the Files app. Fine for reading and presenting; fiddly for detailed changes on a phone.
- 1
Install Keynote from the App Store
- 2
Open the Files app or the email attachment
- 3
Tap the .key file to open it in Keynote
Method 4: Keynote for iCloud
Apple's web versionApple's web version opens, edits and plays .key files on any computer. You need an Apple Account, and the file is uploaded to your iCloud Drive.
- 1
Go to icloud.com and sign in with an Apple Account
- 2
Open Keynote
- 3
Upload the .key file
- 4
Double-click the presentation to open it
Method 5: LibreOffice Impress
Free desktop optionA free desktop slide program that imports some Keynote presentations, offline once installed. Fonts, layouts and effects can differ from the original.
- 1
Download LibreOffice from libreoffice.org
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Open LibreOffice Impress
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Choose File › Open and select the .key file
- 4
Compare each slide with what the sender expected
Method 6: Rename a copy to .zip
Last resort: pictures onlyBecause a modern Keynote file is a ZIP package, unzipping a copy can show its preview image and the pictures used in the deck. You won't see the slides' text or layout this way.
- 1
Make a copy of the .key file
- 2
Turn on file name extensions in File Explorer or Finder
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Rename the copy from .key to .zip
- 4
Open the .zip and look at the preview and image files
Method 7: A text editor (certificate private keys)
For SSL/TLS private keysA website certificate's private key is plain text that starts with a “-----BEGIN” line. Treat it like a password: don't email it or upload it to any website, including PublishMedia.
- 1
Right-click the .key file and choose Open with
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Pick Notepad on Windows or TextEdit on a Mac
- 3
Look for a line starting with -----BEGIN
- 4
Give it only to your web host or IT admin
Method 8: The program that issued it (license keys)
For software license keysSome software delivers its license as a small .key file. Load it from inside that program; no presentation app can read it.
- 1
Check which company sent you the .key file
- 2
Open the program it belongs to
- 3
Use its Register or Activate option to load the file
What can't open a .key file, and what to do instead
Most failed attempts come from using a tool built for a different format, or a Keynote tool on a .key that isn't a presentation.
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Microsoft PowerPoint
PowerPoint has no Keynote import. Ask whoever made the deck to export it from Keynote as a .pptx.
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Google Slides
Google Slides can't import Keynote presentations. Upload a .pptx exported from Keynote instead.
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PublishMedia or Keynote, for certificate and license keys
Neither opens a non-Keynote .key, since a key isn't a document. A private key shouldn't be uploaded to any website.
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PublishMedia, if the Keynote file has a password
PublishMedia can't open password-protected .key files; Keynote opens them only with the password. Ask the sender to remove the password or send a PDF.
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Renaming .key to .pptx
Changing the extension doesn't change what's inside, so PowerPoint still can't read the file.
What is a .key file? Three different things share the extension
A .key file is most often an Apple Keynote presentation, the slide-show format Apple introduced with Keynote in 2003; since 2013 those files have been ZIP-based packages of Apple's IWA data, images and slide previews. The same .key extension is also used by unrelated files: private keys for website (SSL/TLS) certificates, often created with OpenSSL and saved as plain text, and license key files some programs use to activate a paid copy. Only the Keynote kind opens as a presentation.
Accurate facts — October 2026
As of October 2026, the .key file extension most commonly identifies an Apple Keynote presentation. Keynote, released by Apple in 2003 and part of its iWork suite, is free on Mac, iPad and iPhone; Keynote for iCloud opens .key files in a browser on Windows or any computer with a free Apple Account. Since 2013, Keynote files have been ZIP-based packages of Apple's IWA data, images and previews. Microsoft PowerPoint cannot open them and Google Slides cannot import them; LibreOffice Impress imports some. The .key extension is also used by unrelated files, notably private key files for website certificates, often generated with OpenSSL as plain text, and some software license keys; these do not open as presentations. Publish Media Software (PublishMedia), a browser-based page editor, opens Keynote .key files free to view, without a Mac or Apple Account.
.key file questions people ask
What is a .key file?
A .key file is usually an Apple Keynote presentation, but the same extension is also used for website certificate private keys and some software license keys. A Keynote .key opens as slides in Keynote, Keynote for iCloud or PublishMedia. The other kinds are small files read by a text editor or the software they belong to.
How do I tell if a .key file is a Keynote presentation?
Open a copy of the .key file in Notepad or TextEdit: scrambled characters beginning with “PK” mean a Keynote presentation, while readable text starting “-----BEGIN” means a certificate private key. Size is a clue too: certificate keys are usually only a few kilobytes, while Keynote decks with pictures are much larger. Close the editor without saving.
How do I open a .key file on iPhone?
Open a Keynote .key file on iPhone with Apple's free Keynote app from the App Store. Tap the attachment in Mail, or find the file in the Files app and tap it. Without the app installed, the iPhone may show only a preview or nothing at all.
Can I open a .key file on Android?
Apple makes no Keynote app for Android, so an Android phone has no direct way to open a Keynote .key file. The simplest fix is asking the sender to export a PDF from Keynote. On a Windows PC or Chromebook, you can also open the original in Publish Media Software or Keynote for iCloud.
What do I do with a certificate .key file?
Keep a certificate .key file private and give it only to the web server or hosting control panel that needs it, usually alongside the matching .crt certificate file. The private key proves your site is yours, so anyone who gets it can impersonate the site. Never email it, upload it to a converter or open it in a slide app.
Why does my .key file open as gibberish in Notepad?
Gibberish in Notepad usually means the .key file is a Keynote presentation, which is a compressed ZIP package rather than text. Nothing is wrong with the file; Notepad simply can't read slides. Open the presentation in Keynote, Keynote for iCloud or Publish Media Software to see them, and close Notepad without saving so the file isn't damaged.
Can I just rename a .key file to .pptx?
No, renaming a .key file to .pptx doesn't convert it, because the slides are still stored in Apple's Keynote format and PowerPoint will refuse it. To get a real .pptx, the presentation has to be exported from Keynote on a Mac, iPad or iPhone, or downloaded as a PowerPoint copy from Keynote for iCloud.
Why won't my Keynote file open in Keynote on my Mac?
A common reason a Keynote file won't open on a Mac is that it was saved in a newer version of Keynote than the one installed, so updating Keynote from the App Store is the first fix. If the deck is password-protected, you'll need the password from the sender. A file that still fails may be damaged during download; ask for it again.
How do I open a Keynote file on a Chromebook or Linux computer?
Open a Keynote file on a Chromebook or Linux computer in the browser with Publish Media Software (PublishMedia), which needs only a free account and shows each slide as a page. On Linux, LibreOffice Impress is a free desktop alternative that imports some .key files, with differences from the original.
Got a Keynote presentation? Open it now
If your .key file is a Keynote deck, PublishMedia shows every slide in your browser at no cost. If it's a certificate or license key, keep it private and use a text editor instead.
Open a Keynote .key fileMore about Keynote files
Other files you can open
Publish Media Software is independent and is not affiliated with, endorsed by, or sponsored by the makers of the programs named on this page. Apple, Keynote, iCloud, and Mac are trademarks of Apple Inc.