What is a .class file?
A .class file is a java class. Its registered MIME type is application/java-vm, which places it in the application or document family of formats.
CLASS is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
Files of this type usually begin with the bytes CA FE BA BE. That signature is how programs recognise the format even when the extension is wrong or missing.
CLASS file format details
| Extension | .class |
|---|---|
| Format | Java class |
| MIME type | application/java-vm, application/x-java, application/java |
| Category | Application or document |
| Text or binary | Binary |
| File signature | CA FE BA BE |
| Registered with IANA | No |
| Other extensions | None |
How to open CLASS files
| Windows | CLASS files (Java class) are made by specific software. The reliable way to open one is with the program that created it; a generic viewer will only show raw data. |
|---|---|
| Mac | The same applies on a Mac: look for a Mac version of the program that makes CLASS files. |
| iPhone and iPad | Phones rarely open this type of file directly. The viewer above can show what is inside it without installing anything. |
| Android | The same applies on Android. The viewer above shows the first bytes of the file so you can confirm what it is. |
Can you convert a .class file?
TapToConvert does not convert CLASS files. The usual route is to open the file in the program that made it and use its Export or Save as option.
CLASS file FAQ
What is a .class file?
A .class file is a java class, with the MIME type application/java-vm.
How do I open a .class file?
With the program that created it. The viewer on this page shows what is inside without installing anything.
Is a .class file safe to open?
CLASS files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .class?
application/java-vm, and it is also seen as application/x-java or application/java. Web servers send this type so browsers know how to handle the file.
Is CLASS a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.