BREAKING: Excelsior JET 15.3 adds support for Spring Boot and switches to OpenJDK API. Give it a try now.

Deploy Your Java™ Applications as Optimized Native Executables:

to PCs and Macs

to Windows/Linux Servers

to Embedded/IoT Devices

Excelsior JET Embedded

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We also provide professional services, from OpenJDK porting to generic Java consulting.

What Is It?

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

  • Java SE 8 JVM
  • Ahead‑Of‑Time (AOT)
    Java to native code compiler
  • Complete Java SE 8 and JavaFX 8 API implementations from OpenJDK and OpenJFX projects
  • Deployment toolkit
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

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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.

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 native 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 macOS.

Capability ↓
Editions →
Ent Pro Std Emb
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

Collection of technical articles: troubleshooting, FAQs, HOWTOs, etc.

Support Policy

Available support levels and renewal principles


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)