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How to Use Java with OmegaT

The free translation software OmegaT relies on Java to run. Problems with Java are one of the most common problems for people new to OmegaT. If the program does not launch at all, this is likely a Java issue. This article explains how to use Java with OmegaT correctly.

System-wide Java vs. jre subfolder

By default, OmegaT uses the system-wide Java installed in the Program Files folder. But the program can also use local Java, if you put that into the jre subfolder within the OmegaT installation folder such as c:Program Files (x86)OmegaTjre. This is very convenient, because it allows overriding the system-wide Java, if this Java is causing problems.

32-bit and 64-bit Java versions

Java comes both in a 32-bit and a 64-bit version. The 32-bit version runs both under 32-bit Windows and 64-bit Windows, but the 64-bit version runs under 64-bit Windows only. If you are running 32-bit Windows, there is no other option but to use the 32-bit version. If you are running 64-bit Windows, however, you can use any version. But it pays to use the 64-bit one, because it allows allocating more RAM to OmegaT. More RAM means OmegaT will work faster in projects with multiple and/or large source files or translation memories. Read on to see how you can change this option.

Downloading OmegaT with Java

The easiest way to avoid any problems with Java is downloading OmegaT with Java included. Here is how you do it:

  1. Go to the SourceForge download page for OmegaT.
  2. Download the installer called OmegaT_3.0.4_Beta_Windows.exe, where 3.0.4 is the version number that changes over time.
  3. Run the downloaded installer.
  4. Run OmegaT.exe.

Note: Since this version comes with 32-bit Java, you won’t need to worry about Java at all. But, as explained before, using 32-bit Java under 64-bit Windows may be suboptimal.

You can also download our OmegaT version, which contains Java as well. If you have 64-bit Windows, you do not need to make any adjustments. If you are running 32-bit Windows, then follow the instructions in that post.

DIY Java

If the options above do not suit you, here is how you add Java to your OmegaT from scratch:

  1. This instruction assumes that you already have OmegaT installed but without the jre subfolder.
  2. If you do not have Java yet, install the version appropriate to your version of Windows. Download it from Oracle’s website.
  3. Go to the Java installation folder:

c:Program FilesJavajre7

  1. Copy its entire contents to the jre subfolder in OmegaT:

c:Program Files (x86)OmegaTjre

  1. Open the file OmegaT.l4J.ini with any text editor.
  2. Change the option –Xmx_number_M to -Xmx2048M to allocate 2 GB of RAM to OmegaT.
  3. Save this file.
  4. Run OmegaT.exe.

How to check what Java version OmegaT is using

  1. In OmegaT, open Help > Log.
  2. Scroll up to find the first Java information line from the bottom. It looks like this:

Java: Oracle Corporation ver. 1.7.0_25, executed from ‘C:Program Files (x86)OmegaTjre’ (LOG_STARTUP_INFO)

  1. The path tells which Java OmegaT is using. It does not tell you whether it is 32-bit or 64-bit, though.

You can ask any questions about OmegaT on our Facebook page.

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About the Author

Roman Mironov
Roman Mironov
CEO & Founder

As the founder of Velior, Roman has had the privilege of being able to turn his passion for languages into a business. He has over 15 years of experience in the translation industry. Roman has helped dozens of clients increase sales by making their products appealing for speakers of other languages.