MSI to JAR Converter
Processing entirely on your device — large files may take a moment.
MSI is the Windows Installer database: a COM-structured file holding the program files, registry entries and install logic of an application. Everything an installer would unpack lives inside it. Repack a JAR as ZIP to inspect classes and resources with any unzip tool.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How MSI compares to JAR
| MSI | JAR | |
|---|---|---|
| Compression | Storage + CAB payloads | DEFLATE entries |
| Bundling | COM structured storage | Classes + resources |
| Best for | Windows software distribution | Java apps and libraries |
How to convert MSI to JAR
- 1
Select your files
Drag & drop your MSI files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to JAR". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted JAR file individually, or grab everything at once as a ZIP archive.
About the MSI format
MSI is the Windows Installer database: a COM-structured binary that holds every file, shortcut, registry entry and install sequence an application needs. Running the installer is one way in — extraction is the other, and it needs no Windows at all.
Extracting an MSI lays out its contents as files: binaries, DLLs, resources, even the install logic tables. Security teams audit them this way, IT departments pre-stage deployments this way, and curious users finally learn what "installing" actually does.
+ Strengths
- ✓Inspect installers without running them
- ✓Works cross-platform — no Windows needed
- ✓Files come out exactly as the installer would lay them
! Limitations
- −Registry and shortcut logic are not files
- −Large installers extract to large trees
- −Nested CAB payloads may need a second pass
About the JAR format
A JAR is a ZIP with Java manners: class files, a MANIFEST.MF, resources and optional signatures. Any tool that opens ZIPs can open it — but converting to a plain ZIP strips the “is this executable?” ambiguity and makes browsing the contents painless.
Useful for auditing dependencies, extracting embedded resources, or checking what a library actually ships before adding it to a build.
+ Strengths
- ✓Standard Java delivery format
- ✓ZIP-based, tools abound
- ✓May carry signatures and manifests
! Limitations
- −Not a installer — just a package
- −Contents are class files, not source
Why convert MSI to JAR?
Think of it as moving your file to the container that fits the job. Registry and shortcut logic are not files JAR works differently: Standard Java delivery format If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this MSI to JAR converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for MSI to JAR?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Is there a size limit for archive conversion?
There is no upload cap because nothing is uploaded — the practical limit is your device memory. A few hundred megabytes of unpacked content works comfortably on a modern computer.
Are the files inside my MSI archive modified?
No. Contents are unpacked in memory and repacked into JAR byte-for-byte — the conversion changes the container, never the files inside it.