Memory manager scalability has got a boost in Excelsior JET 14. Give it a try or learn what else is new.

Excelsior JET enables you to distribute and deploy your Java™ applications as optimized native executables that start and work faster, do not depend on the JRE, and are as difficult to reverse engineer as if they were written in C++.

Download Your Fully Functional 90-Days Trial Now  or  Check Prices

What Is It?

Excelsior JET is a complete implementation of the Java SE technology for Microsoft Windows, Apple OS X, and Linux. It includes:

  • Java SE 8 compatible JVM
  • Ahead‑Of‑Time (AOT)
    Java to native code compiler
  • Complete Java SE 8 and JavaFX 8 API implementations, licensed from Oracle
  • Deployment toolkit

Excelsior JET has passed the official compliance tests (JCK) and is certified Java Compatible.

More on compatibility »

Excelsior JET Optimizer

How It Works

First, the AOT compiler turns your jar and class files into a conventional binary executable. That executable is fully interoperable with our JVM, which includes a JIT compiler to handle any classes that were not precompiled.

Second, the deployment toolkit helps you create an installer containing the application executable, necessary runtime files, and the auxiliary files of your choice — data files, documentation, license, etc.

Look under the hood »

Data Sheet PDF | Frequently Asked Questions | Changelog | Roadmap

Never miss a new release or a maintenance update. Subscribe to Excelsior JET email alerts:

Java Compatible Logo

You may be wondering what it takes to get this little Java Compatible logo and, more importantly, what benefits it delivers to you as a user of our product. These are the key points:

Shapes and holes


Excelsior JET has passed the Java SE 8 Technology Compatibility Kit (JCK) test suite.

The JCK comprises over 200,000 individual test cases verifying compliance with all aspects of the Java specification. Technically, this means that any program coded in accordance with the Java specification must produce the same result on the reference implementation and when natively compiled with Excelsior JET.


The standard Java SE class library included in Excelsior JET is built from the same source code as the one included in the Oracle JRE.

The reuse of the reference implementation source code not only has helped our product pass the JCK tests. It also makes Excelsior JET replicate any loosely specified or implementation-defined behavior of the standard Java library classes as implemented in the Oracle JRE automatically.

Notice The JCK is not a stress test. It does not benchmark the implementation's performance or throughput.

Protection Against Java Decompilers Peace of mind

Java class files are easy to reverse-engineer. The very properties that enable Java applications to run anywhere make reverse translation straightforward. There are a number of Java decompilers on the market that produce amazingly readable source code.

In contrast, reverse translation of optimized native code is a hard engineering task that cannot be automated like Java bytecode decompilation.

An obfuscator can make the decompiled code less comprehensible. However, name obfuscation may cause reflection and JNI failures, whereas extensive control flow obfuscation negatively impacts performance and may provoke a VerifyError. To make things worse, these problems only manifest themselves when the respective class is actually loaded at application run time, and thus may slip through the QA process. And reverse engineering of an equivalent C++ program passed through an optimizing compiler would still be more difficult.

Excelsior JET gives you the best of both worlds. With it, you reduce the set of class and jar files comprising your Java application to a solid binary executable before shipping it to customers or delpoying it to production servers. You avoid the obfuscation trade-offs: reduced performance and increased risk of run-time errors. You may continue using tools that encrypt strings and resources, and you may pass classes not accessed via JNI or reflection through a name obfuscator if you know what you are doing.


Excelsior JET, Enterprise Edition enables you to protect not only plain Java applications, but also Eclipse RCP applications and Tomcat Web applications. You can find more information and examples on the dedicated pages:

The most secure way to deploy Eclipse RCP apps

Protect your Web apps against decompilation and tampering

Improved User Experience Faster startup, smaller footprint, no dependencies

Performance Gain

Notice All charts represent data gathered by running particular applications in specific environments. Your mileage will vary.

Natively precompiled Java code runs directly on hardware right from the start. The absence of the warm-up cycle and JIT compilation overhead results in faster application startup and optimal code performance.

Excelsior JET is the only product that supports Java SE 8 Compact Profiles for desktop and server applications. Compact profiles enable you to omit parts of the Java SE standard library that are not used by your application, reducing its download size and disk footprint.

The run time memory footprint is also somewhat smaller because the Excelsior JET JVM is leaner compared to traditional implementations.

Finally, the applications precompiled with Excelsior JET do not require the JRE, and the included deployment tools help you package your optimized application together with the necessary runtime files into a naitve installer.

Featured Success Story

Excelsior JET is available in three editions. Licenses for each platform are sold separately; discounts apply to multiplatform bundles. The licenses are perpetual and come with one year of support and upgrades.

Excelsior JET, Professional Edition for Windows with 1 Year of Standard Support

New License


  • Price is per developer seat, no runtime royalties*
  • Includes one year of support and upgrades
  • Perpetual license, support renewal optional

Buy Now

or check if you qualify for a discount or free license

Support Renewal


Notice New support period begins where the previous one left off.

Renew Support

* Notice The Excelsior JET Runtime License prohibits deployment to and bundling with embedded systems. If you are targeting devices with dedicated functionality, check out Excelsior JET Embedded.

You can test Excelsior JET thoroughly prior to purchase.  Download Your 90-days Evaluation Copy Now

Microbusiness Licensing Program

MicroISVs, early stage startups, and other very small businesses employing just a few software engineers may purchase Excelsior JET at reduced prices.

Apply Now  or Learn More

Non-Commercial Use

We gladly provide Excelsior JET licenses at no cost to authors of free, non-commercial Java applications that meet a few simple qualification criteria.

Get A Free License Now

Personal Licenses

You can opt-in to receive a free Excelsior JET, Standard Edition license for your personal use when downloading Excelsior JET Evaluation Packages.

Register Now

Notice Only 64‑bit Professional and Enterprise Editions are available for OS X.

Capability ↓
Editions →
Ent Pro Std
Generates 64-bit (x64) native executables
Protects plain Java SE and JavaFX applications from decompilers

These are just the major differences. Refer to the Feature Matrix for an exhaustive list.

Knowledge Base

A collection of technical articles: troubleshooting, FAQs, HOWTOs, etc.

Support Policy

Available support levels and renewal principles

Video Tutorials

Detailed, step-by-step instructions on particular usage scenarios


Ask questions and share your knowledge in peer-to-peer forums

Product Updates

Download maintenance releases and patches


Read product manuals on-line or download to your computer

Email Support

Reach out to the Excelsior JET engineeering team for help

You can test drive our support for up to 90 days. Just  Download Your Evaluation Copy and fill in a short questionnaire.

Technical Support

Experiencing a technical issue, or have a question to our engineers? Email them at the above address, or select Open Support Ticket from the Help menu.

Customer Service

Inquiries about pricing, licensing, payment methods, order status, product delivery, support renewals, etc.

General Inquiries

All other issues.


Dmitry Leskov
Director of Marketing
+1 (408) 786 5641 skypein
(4am-4pm GMT)