Opening C9R Files

The C9R file type is primarily associated with Cryptomator.

C9R	File extension: C9R
	File type:	Cryptomator E2EE file

What is a C9R file?

C9R files mostly belong to Cryptomator by Skymatic. C9R is a Cryptomator E2EE file - it's a cryptographic container for computer files, that encrypts both files and filenames with AES and 256 bit key length. C9R mnemonic: C, followed by 9 letters, then ending in an R.

How to open C9R files

You need a suitable software like Cryptomator to open a C9R file. You need a suitable software like Cryptomator from Skymatic to open a C9R file. Without proper software you will receive a Windows message "How do you want to open this file?" or "Windows cannot open this file" or a similar Mac/iPhone/Android alert. If you cannot open your C9R file correctly, try to right-click or long-press the file. Then click "Open with" and choose an application. You can also display a C9R file directly in the browser:. Just drag the file onto this browser window and drop it.

Online C9R Text Viewer

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What to Do When a .C9R File Fails to Open

Because .C9R files can originate from different programs, they aren't universally openable.

Identify the Source: Files from cloud backups or secure sharing workflows are likely Cryptomator E2EE files.
Check the Header: Inspect the first bytes in a text or hex editor:
- Random characters indicate encrypted data.
- "PK" suggests a zipped archive.
- Readable JSON points to a configuration file.
Use the Original Software: The original program is usually required; try Skymatic Cryptomator, or ask the sender if uncertain.
Use this Webpage: Drag and drop your .C9R file into our viewer to detect the format, extract readable metadata, and preview contents.

Technical Data for C9R File Extension

File classification:

Cryptographic Container

Related files:

idf, xpl

a c9r Cryptomator E2EE file is a special file format by Skymatic and should only be edited and saved with the appropriate software.

How to solve problems with C9R files

Associate the C9R file extension with the correct application.
Update your software that should actually open cryptomator e2ee files. Because only the current version supports the latest C9R file format. Search, therefore, e.g. on the Skymatic manufacturer website after an available Cryptomator update.
To make sure that your C9R file is not corrupted or virus-infected, get the file again and scan it with Google's virustotal.com.
Click here to open your .C9R file online - secure, fast, and no downloads needed.