What is a .key file?
Apple Keynote Presentation · Document · Apple · 2003
A .key file is a presentation from Apple's Keynote app, the iWork alternative to PowerPoint. It is a package format that opens on Mac, iPad, iPhone and iCloud, but not natively on Windows.
What is a .key file used for?
Keynote is known for polished animations and templates. A .key file bundles the slides, media and transitions as a package.
Windows has no Keynote app, so the usual path is iCloud Keynote in a browser, or exporting to PowerPoint (.pptx) or PDF.
What opens a .key file?
The .key format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- iCloud Keynote (web)
- convert to PPTX first
macOS
- Apple Keynote
- Preview (quick look)
Linux
- iCloud Keynote (web)
Web
- iCloud.com Keynote
Open a .key file step by step
- Confirm the file really is a .key. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with iCloud Keynote (web) or convert to PPTX first.
- On Mac, use Apple Keynote or Preview (quick look).
- On Linux, try iCloud Keynote (web).
- Still stuck? Convert the .key to pptx, which opens more widely.
Why can't I open my .key file?
Almost always because no installed app understands Keynote. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .key at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .key file
You can convert a .key file to pptx, pdf, mov using a conversion tool or the export menu of an app that opens it.
What is the .key file signature (magic bytes)?
A .key file starts with the hex bytes 50 4B 03 04, which read as PK.. in ASCII. Programs identify Keynote by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for Keynote. For a full breakdown, see the ZIP file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 50 4B 03 04 | 0 | PK.. | ZIP package (PK..) |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .key file?
A .key file is a presentation from Apple's Keynote app, the iWork alternative to PowerPoint. It is a package format that opens on Mac, iPad, iPhone and iCloud, but not natively on Windows.
How do I open a .key file on Windows?
Use iCloud.com Keynote in a browser, or ask the sender to export it to PowerPoint (.pptx) or PDF from Keynote.
Can PowerPoint open a .key file?
Not directly. Export it from Keynote as .pptx first, then PowerPoint opens it, though complex animations may not survive.
What is a .key file?
A presentation made in Apple Keynote, part of the free iWork suite on Mac, iPad and iPhone.
Related formats
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