Despite the rise of cloud-native and microservices architectures, mainframes continue to run the core systems of some of the world’s most important industries—from banking and insurance to government and healthcare. These systems, often written in COBOL, PL/I, or Assembler, are not going anywhere soon.

However, testing mainframe applications has traditionally lagged behind in automation, agility, and integration with modern DevOps pipelines. But that’s changing. A new generation of mainframe testing tools is emerging, designed to support automated testing, CI/CD, and modernization initiatives.

In this article, we explore five top-tier mainframe testing tools in 2025. We will cover their strengths, technical capabilities, and where each fits in the modernization roadmap.

Is Mainframe Testing Important?

Mainframes remain essential for:

  • High-volume transaction processing (e.g., ATMs, credit card processing)
  • Batch jobs run billions of dollars in operations daily
  • Regulatory systems requiring extreme uptime and reliability

Failures in these systems can result in millions of dollars in losses, customer dissatisfaction, and compliance issues. Therefore, rigorous and frequent testing is non-negotiable. But testing mainframe applications poses unique challenges:

  • Steep learning curve due to legacy technologies
  • Lack of test environments and data
  • Dependency on costly MIPS consumption
  • Limited automation compared to modern web or mobile apps

This has prompted a significant push toward test automation, virtualization, and CI/CD integration.

Mainframe Testing Tools

Let us review the top 5 mainframe testing tools and help you choose the best suitable tool for your needs.

1.testRigor

Overview

While testRigor is known for web, desktop, database, API, and mobile automation, it’s increasingly being used to test mainframes and its UIs—all with plain English test scripts. This opens mainframe testing to non-technical users, business analysts, and QA teams with little COBOL knowledge.

Key Features

  • No-code test case creation using plain English
  • Supports mainframe testing: field inputs, navigation, assertions, etc.
  • End-to-end testing across mainframe, web, mobile, desktops, and APIs
  • Test data management, reusability, and full CI/CD support

Use Case

A telecom giant uses testRigor to validate customer provisioning across a green-screen mainframe interface and a modern web app, within a single test suite.

Pros

  • Enables non-technical users and everyone on the team to write tests
  • Seamless cross-platform testing
  • Powerful for regression, smoke, E2E, UI, and user journey validation

Limitations

  • Not suitable for performance testing

2. Micro Focus Enterprise Test Server

Overview

Micro Focus‘s Enterprise Test Server allows organizations to offload testing from the mainframe onto distributed environments (e.g., Windows). It emulates a full z/OS stack, enabling end-to-end testing without burning expensive MIPS.

Key Features

  • Support for COBOL, PL/I, JCL, CICS, IMS, DB2
  • Full z/OS emulation on x86 architecture
  • Integration with Eclipse, Visual Studio, Jenkins, etc.
  • Automated batch and online transaction testing

Use Case

A Fortune 500 bank uses it to simulate production behavior in an isolated QA environment, reducing test execution costs by 60%.

Pros

  • Reduces reliance on physical mainframes
  • Enables shift-left testing
  • Excellent DevOps compatibility

Limitations

  • Requires configuration expertise
  • Licensing can be complex for large teams

3. IBM Z Virtual Test Platform

Overview

IBM’s Z Virtual Test Platform (ZVTP) enables unit and integration testing without the need for all backend dependencies. It captures test artifacts and replays them in a virtualized environment.

Key Features

  • Virtualizes mainframe resources (CICS, MQ, DB2)
  • Capture-and-replay test data capabilities
  • Works with IBM Wazi and UrbanCode for DevOps
  • API-driven testing

Use Case

An insurance company uses ZVTP to validate business logic in COBOL apps during nightly builds, reducing test cycle time from 2 weeks to 3 days.

Pros

  • Minimizes test environment setup
  • Enables earlier testing (shift-left)
  • Great for regression testing

Limitations

  • Still primarily focused on the IBM ecosystem
  • Requires investment in a virtualization setup

4. Compuware Topaz for Total Test

Overview

Now under BMC, Topaz for Total Test is a comprehensive test automation solution that transforms mainframe testing from manual to automated processes, especially for COBOL.

Key Features

  • Unit, functional, and regression testing
  • Mocking of DB2, VSAM, CICS
  • Integration with Git, SonarQube, Jenkins
  • Part of the BMC AMI DevX suite

Use Case

A global retail chain uses it for continuous integration of its pricing engine, built on COBOL, running hundreds of tests per commit.

Pros

  • Developer-friendly
  • Rich UI for writing and executing tests
  • CI/CD ready

Limitations

  • COBOL-focused (less coverage for PL/I or Assembler)
  • Deep learning curve for mocking

5. Heirloom Computing + JUnit

Overview

Heirloom’s Elastic COBOL compiles COBOL applications into Java bytecode, allowing legacy apps to be tested using standard Java tools like JUnit, IntelliJ, and Maven.

Key Features

  • Transpilation of COBOL to Java
  • Compatible with JUnit, Jenkins, GitHub Actions
  • Cloud deployment support (AWS, Azure, GCP)
  • Real-time debugging and hot code reload

Use Case

A U.S. federal agency used it to migrate COBOL business logic to Java-based test automation without rewriting core systems.

Pros

  • Great for modernization projects
  • Uses familiar tools for Java developers
  • Enables test-first development in COBOL apps

Limitations

  • Requires reengineering or transpiling the codebase
  • Not ideal for shops with large Assembler codebases

Mainframe Testing: 2025 Trends

1. Shift-Left Adoption

With platforms like IBM ZVTP and Topaz, companies are starting to run tests earlier in the development cycle—even before integration.

2. Cross-Skill Automation

Tools like testRigor enable QA engineers, business analysts, and even product owners to define and automate tests, bridging the skills gap.

3. Cloud-Native Mainframe Modernization

Solutions like Heirloom and Micro Focus allow legacy apps to be run and tested in cloud containers, making it easier to scale environments.

4. CI/CD Integration

Mainframe testing tools are now integrating with Jenkins, GitLab CI, Azure DevOps, and GitHub Actions—breaking down silos.

5. AI in Testing

Expect AI-assisted test generation, defect prediction, and self-healing scripts to gain traction in tools like testRigor and IBM Z AI Ops.

Best Practices for Mainframe Testing in 2025

  • Virtualize test environments to avoid dependency on production systems
  • Automate test data generation for repeatability
  • Mock dependencies (e.g., DB2, CICS) where appropriate
  • Use no-code platforms for business logic validation
  • Integrate tests into your CI/CD pipelines
  • Prioritize E2E test coverage across all connected systems

Summary of Tools to Help You Choose

  • Accessibility: testRigor provides plain English scripting. It is ideal for teams without deep mainframe or programming expertise.
  • Cost Reduction: Micro Focus offloads mainframe processing, reducing operational costs.
  • Speed & Feedback: IBM ZVTP enables quick regression without backend dependencies.
  • Developer Experience: Topaz offers strong tooling for COBOL teams with CI/CD integration.
  • Modernization: Heirloom transforms COBOL apps into Java, ideal for cloud migration.

Conclusion

Mainframe systems are not relics of the past. They are essential to the modern enterprise. However, testing them can no longer rely on outdated manual processes. Whether you’re maintaining legacy COBOL applications or transforming your mainframe stack for the cloud, the right tools can make all the difference.

From legacy leaders like Micro Focus and IBM ZVTP, to modernization bridges like Heirloom, and developer-friendly solutions like Topaz, each tool brings its strengths. But platforms like testRigor are redefining accessibility, making mainframe testing inclusive, faster, and part of the broader DevOps movement.

If you are serious about achieving mainframe testing excellence in 2025, consider combining these tools based on your ecosystem and skills. And don’t underestimate the power of low-code automation in complex, high-stakes environments.