COBOL Migration Portal

Migration and Performance Tuning Webinars

Watch recorded webinar videos or connect with IBM COBOL experts directly

Why you should migrate

In this video, Roland Koo, the Program Director in Offering Management and Strategy for Enterprise Products and Compilers on IBM® Z®, explains why it is important to migrate to the COBOL latest version as you upgrade your IBM Z hardware.


  • Applications may not automatically run faster after they are moved to new IBM Z hardware.
  • IBM Automatic Binary Optimization for z/OS® (ABO) can help optimize code that has not been touched or recompiled for a long time.
  • The latest COBOL 6 compilers can help modernize your business critical applications to accelerate digital transformation, including native support for XML and JSON, 64-bit code generation, UTF-8, etc. Discover the lastest features in COBOL 6 in the What's New manual.

Customer stories

Learn from our world-class clients about the benefits of migrating to the latest version of COBOL.

How to migrate

In this video, Captain COBOL, Tom Ross describes how to migrate from COBOL 4 and earlier versions to COBOL 6.


  • Use the two-compile and two-test process to verify the data at run time.
  • Leverage IBM DevOps tools to make building and testing easier.

For more details, read Tom and Roland's blog.

Kickstart your COBOL migration

COBOL Migration Assistant

Log in with your IBM ID and use the step-by-step wizard to guide your migration process.

Use IBM Automatic Binary Optimizer for z/OS (ABO) to accelerate your COBOL migration

Accelerate COBOL migration by using the latest version of COBOL for new development, modernization, and maintenance, and ABO (sold separately) to improve the performance of the modules without a recompilation plan.

Explore more:

ABO product page

ABO customer success stories

Apply IBM DevOps tools to support your COBOL migration

Apply IBM DevOps tools to manage your applications much easier and improve efficiency, including automated testing, which is key to COBOL migration.

IBM Z Virtual Test Platform (ZVTP, formerly known as Wazi Virtual Test Platform) allows a developer to record the transactions and batch programs within their application and replay them in a virtualized environment without the need for middleware - allowing application changes to be tested before they are deployed.

Use IBM Z Virtual Test Platform and efficiently run regression testing without impact on existing test environments after your COBOL compiler upgrades. 

    1. Use IBM ZVTP to capture various execution paths of an application using modules compiled with COBOL 4 or earlier versions.
    2. Upgrade your COBOL code with the new compiler into a set of load libraries that are not attached to a specific test environment.
    3. Use the recorded ZVTP tests to replay the application using the newly compiled COBOL modules.
    4. ZVTP automatically verifies that the new COBOL load modules function the same as before the upgrade by comparing the argument values from program calls and middleware calls against the recorded values. These tests are run by virtualizing the middleware and does not require any special application relinking or rebinding.
    5. Once verified, a specific test environment can be upgraded to the new compiler for end to end regression tests involving the subsystems.

Learn about the latest features in IBM ZVTP

What to do after you migrate

Explore more opportunities after you migrate

Looking for more help

Check out additional resources


COBOL product page

COBOL support library