How to open a .JAR file online
No extra software to download or install.
Pick your .JAR file
Drag it in or click to choose it. We read its contents list first, so it opens right away without unpacking everything.
Browse what's inside
See every file with its size, how much it's compressed and its date, and search by name across all the folders.
Preview or download
Click a file to preview text or images, or save just that one. Need everything? Download it all as a single ZIP.
About .JAR files
What a .JAR file is, and what's inside it.
A JAR file is a Java Archive, a ZIP bundle of compiled Java bytecode (.class files), resources, and a manifest. To run an executable JAR you need Java installed (OpenJDK/Temurin is free), then either double-click it or run `java -jar app.jar` in a terminal. To just look inside, rename it to .zip or open it with 7-Zip.
Programs that open .JAR files
| Full name | Java Archive |
|---|---|
| Developer | Sun Microsystems (now Oracle); JAR spec part of the Java Platform |
| First released | 1996-1997 (JDK 1.1) |
| Category | Archives |
| MIME type | application/java-archive |
| Signature | 50 4B 03 04 "PK" - standard ZIP local file header |
Related viewers
Found something inside the archive? Open it here.
Do I have to unpack the whole .JAR file?
No. The viewer reads its table of contents first and only unpacks a file when you click it. That works even with multi-gigabyte archives, because we read just the bytes we need.
Can I open password-protected archives?
Yes, for ZIP (ZipCrypto and AES) and 7Z. You'll be asked for the password,. We can't recover forgotten passwords.
Is my .JAR file uploaded anywhere?
No. The code that unpacks the file is downloaded once and then reused.
Why does a .docx or .apk open as an archive?
Because they are ZIP archives under the hood. Office documents, Android apps, Java programs and EPUB books all use ZIP as their container.
What about split archives (.001, .z01, .part1.rar)?
Multi-part archives need all their parts. Today you can open the first part to see the file list; joining parts is on our roadmap.
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