.key File Extension
.key file is, how to open an Apple Keynote presentation, how Poly supports it, and when to export another format. File extension details for .key
Partial Support| File type | Apple Keynote presentation |
|---|---|
| MIME type | |
| Encoding | Binary ZIP-based document, or a macOS package directory |
| Operating systems | macOS, iOS, iPadOS, Windows via iCloud |
| Opens with | Apple Keynote, Keynote for iCloud |
| Poly support | Partial. Poly recognizes and processes supported single-file Keynote presentations. |
| Indexed by Poly | Yes, when processing succeeds. Poly indexes slide text, OCR results, and page-level similarity. |
| Preview in Poly | Partial. Poly provides thumbnails and a connected presentation preview on a best-effort basis. |
| Poly agent | Yes, when processing succeeds. The Poly agent can read slide text and rendered slides. |
What kind of file is a .key?
A .key file is usually an Apple Keynote presentation. It can contain slides, text, images, charts, tables, audio, video, presenter notes, animations, and transitions. Current single-file presentations use the registered application/vnd.apple.keynote MIME type.1
IANA describes that format as a binary ZIP archive, but Apple does not publish a complete format specification. The common ZIP opening bytes 50 4B 03 04 are therefore only a clue. DOCX, EPUB, and ordinary ZIP archives can begin the same way. Software should also inspect the archive structure and use the media type and filename as evidence.
.key does not convert it into a Keynote presentation. Export it with an application that understands the source format.How do I open a .key on my computer?
On a Mac, iPhone, or iPad, open the file with Apple Keynote. Apple says current versions of Keynote can open presentations created by every Keynote version.2
On Windows, use Keynote for iCloud in a supported desktop browser. Upload the file to iCloud, then open it in the Keynote web app. A browser does not natively render .key data merely because you navigate to the file.
Keynote normally saves a presentation as one file. On macOS it can instead save a large deck as a package directory. Apple suggests this option for presentations over 500 MB or those with large media, but notes that some web and email services cannot transfer packages.3 Change it back to Single File in Keynote before uploading when needed.
Poly support for .key
Poly recognizes .key presentations and gives supported single-file decks thumbnails, a best-effort connected preview, slide-text extraction with OCR fallback, and page-level visual search. After processing succeeds, the Poly agent can use the extracted text and rendered slides.
Native animations, transitions, interactive media, and the editable Keynote package are not reproduced for the agent. Password-protected, damaged, package-directory, or incompatible presentations may not process. Keep Keynote available when exact playback or editing behavior matters.
History of .key
Apple introduced Keynote on January 7, 2003 as a Mac presentation application. Its first release included 12 themes, animated charts and tables, speaker notes, multimedia, and PowerPoint and PDF exchange.4
The current application/vnd.apple.keynote media type was registered in 2018. IANA records .key as its extension and application/x-iwork-keynote-sffkey as a deprecated alias. Older Keynote documents stored as directories are outside that registration.1
Working with .key and alternatives
Choose an export based on what the recipient needs:
| Format | Best for | Main tradeoff |
|---|---|---|
PowerPoint (.pptx) | Continued editing outside Keynote | Fonts, effects, and layouts may change |
| Stable review, printing, and sharing | Animations and editable slide objects are lost | |
| PNG or JPEG | Individual slides as images | Text and objects are flattened |
| Movie or animated GIF | Sharing motion and timing | The presentation is no longer editable as slides |
Apple supports exporting Keynote presentations to PowerPoint, PDF, images, animated GIF, movie, and, on Mac, HTML. Conversion creates a copy and leaves the original intact.2 Review the result for font substitutions, shifted layouts, missing notes, and changed animations.
.key original for editing and export a PDF copy for a stable reading experience.Footnotes
- Internet Assigned Numbers Authority.
application/vnd.apple.keynoteMedia Type Registration. The registration documents the extension, binary ZIP-based format, deprecated alias, and lack of a public specification. ↩ ↩2 - Apple Support. Convert Pages, Numbers, or Keynote Files to Microsoft Word, Excel, PowerPoint, PDF, and More. Apple documents supported Keynote input and export formats and browser-based conversion. ↩ ↩2
- Apple Support. Save a Large Keynote Presentation as a Package File on Mac. Apple explains single-file and package storage and the 500 MB guidance. ↩
- Apple. Apple Unveils Keynote. Apple's 2003 announcement describes the original release and feature set. ↩