Java Class File — Compiled Java bytecode class file.
Quick facts
What is .class
A .class file is a Java Class File — Compiled Java bytecode class file.
In the mime-db registry it maps to application/java-vm, and it is marked as non-compressible. When serving .class over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to application/java-vm — and is delivered over HTTP via the Content-Type header.
How to open .class files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: application/java-vm
Common software that reads/writes .class:
Relation chain
Related extensions
Related MIME types
Common uses
How to edit .class files
How to create .class files
Frequently asked questions
Common options include Java, IntelliJ IDEA. You can also open many of these files with built-in viewers or a browser.
Create a new file in any text editor or the app that owns the format and save it with the .class extension.
application/java-vm is the media type identifier used for .class files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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