Why migrate VB6 to .NET code in 2024

Abto Software
4 min readMay 31, 2024


This post is a quick overview of an Abto Software blog article.

In response to the current volatile market conditions, business leaders are focusing on shrinking their expenses and optimizing everyday workflows.

To date, many organizations across industries continue utilizing Visual Basic 6.0 (VB6) as their primary platform. While most larger organizations often have the expertise to abandon Visual Basic 6.0 favoring other platforms, smaller companies are facing serious challenges.

VB6 applications becoming irrelevant

Be it discontinued support, the need to uncover modern capabilities, or ever-evolving regulatory requirements, business leaders are confronting the obsolescence of their legacy applications.

Visual Basic versions 1.0–6.0 were widely popular throughout the 1990s and 2000s until retirement in 2008. Visual Basic, being simple and versatile, was used to build desktop and database applications, games, utilities, and custom business applications.

VB6 applications getting abandoned across industries

The trend towards migration is gaining more and more momentum:

  • Visual Basic is obsolete, with increasing security vulnerabilities
  • Its security score of 9.3 indicates high risks of breaches impacting reputation and finances
  • Visual Basic doesn’t receive regular updates and patches
  • It’s unable to handle object-oriented programming, exception handling, as well as multi-threading, which, accordingly, affects performance

With rapidly growing concerns towards compliance, more organizations are moving to more modern platforms. Forward-looking companies, no matter the domain, are transitioning from objectively deprecated technologies to ensure desirable performance and security.

.NET conversion becoming inevitable?

Visual Basic has long been popular and preferred for the following reasons:

  • User-friendly interface and uncomplicated programming environment
  • Pre-built controls (buttons, labels, text boxes)
  • Rapid Application Development (RAD), which enables to quickly build prototypes and applications
  • Integrated Development Environment (IDE), which enables the design, coding, testing, and deployment of applications all within one platform

But inevitably, Visual Basic being unsupported is causing several constraints:

  • System stability and reliability
  • System integration with more modern technologies
  • The need for modern user interfaces and features
  • The difficulty in meeting regulatory requirements

.NET conversion: diving deeper

System stability

Visual Basic 6 software doesn’t receive regular updates and patches, which generates security vulnerabilities. On the other hand, the modern .NET framework offers updates and patches, comprehensive documentation, and support, among many other features.

System integration

Visual Basic 6 software lacks compatibility with modern, contemporary technologies, entangling integration. The modern .NET framework, in contrast, supports OAuth, OpenID Connect, REST APIs, cloud-based services, and more.

User interfaces and features

VB6 applications are characterized by their insufficient support for modern user interfaces and functionality. .NET provides extensive controls and libraries, cross-platform capabilities, smooth integration with modern client-side technologies, and more.

Regulatory requirements

VB6 programs are lacking data encryption, audit trails, and other critical features to meet legal requirements. .NET provides robust features that ensure regulatory compliance, for example data encryption, audit logging, and more.

The approach to smooth VB6 to VB.NET migration

Automated migration

Automated migration means utilizing specialized instruments to convert VB6 code into adequate .NET code. This process typically involves the analysis of the existing codebase, the identification of elements to migrate, and the subsequent translation into equivalent .NET code.

This type of migration preserves functionality, ensures consistency, and minimizes manual efforts and errors. But nonetheless, this approach does require additional improvements, for example removing duplicates, upgrading syntax and controls, and fixing data declarations.

Manual migration

Manual migration means implementing manual techniques to transform VB6 code into appropriate .NET code. The process usually involves the analysis of the existing codebase as well as underlying business functionality.

Manual migration must follow automated migration for refinement, customization, optimization, and more. This approach does require specific expertise, however, carries great importance.

Data migration

Data migration is another important stage, which might become challenging if lacking specialized expertise:

  • Schema conversion to a format compatible with the .NET environment
  • Data extraction from existing data sources in the VB6 application
  • Data transformation to match data structure and formats being required by the .NET application, typically including data cleansing and normalization
  • Data loading into the data storage being used by the .NET application, which includes inserting records into databases, uploading files, and changing data formats
  • Data validation to ensure data accuracy and integrity
  • Data synchronization to ensure data consistency and avoid data loss and duplication

Quality assurance

Quality assurance, a stage that shouldn’t be neglected, isn’t that technically complex, but important to enable:

  • Data integrity by eliminating data loss, corruption, duplication, and inconsistencies
  • Risk management by identifying security vulnerabilities, compatibility issues, functional regression, performance degradation, and other potential problems
  • Application functionality by addressing any inconsistencies and ensure expected behavior
  • Regulatory compliance by implementing mentioned practices

Before approaching VB6 to .NET migration

Another takeaway we’ve mentioned in one of our recent articles when discussing VB6 to .NET migration — functional equivalence is the first priority.

Approaching migration, business leaders might prefer to rewrite separate parts of their legacy applications. This means time-to-market delays, budget overruns, unexpected bottlenecks, and also resource constraints, but not if you’re first migrate and only then rewrite the application.

How we can help

Abto Software has proven technical expertise for transitioning mission-critical applications without disruption.

Our engineers handle discovery and planning, code assessment and preparation, and smooth VB6 migration. Our clients forget about operational and performance shortfalls, security vulnerabilities, compatibility issues, and other business burdens associated with maintaining legacy VB6 applications.

We cover:

  • Business analysis and consulting
  • Project setup and kick-off
  • Code migration
  • Code finalization
  • Acceptance testing and improvement
  • Quality assurance and deployment

You enjoy:

  • Higher performance and efficiency
  • Expanded functionality and scalability
  • Improved security through updates and patches
  • Enhanced compatibility across platforms and devices
  • Long-term support and maintenance
  • Cloud compatibility



Abto Software

We empower customers business with innovative software by applying science, R&D, and own IP at abtosoftware.com