Program logic
Readable reconstructed code, procedure structure, calls, conditions, strings, APIs, and low-level disassembly for verification.
A practical recovery guide
How to Choose a VB6 Decompiler
You do not need to know whether your old VB5/6 application contains P-Code or Native Code. VB Decompiler detects the format and supports both. The important question is simpler: what can realistically be recovered from your EXE, DLL, or OCX, and how much manual work will remain?
First, set the right expectation
A decompiler does not recreate the original project exactly. It reconstructs the maximum useful amount of code and project information that remains in the compiled file. The result normally cannot be opened in the VB5/6 or Visual Studio IDE and recompiled immediately. It must be reviewed, corrected, and integrated into a new project by a developer.
Compilation removes comments, formatting, many original names, and some source-level decisions. A decompiler also has to translate thousands of compiler and runtime patterns back into readable code. Even very strong recovery therefore leaves incompatibilities or incorrectly reconstructed fragments that require manual investigation.
Realistic recovery ranges
| Compiled application | Approximate recoverable code | What remains |
|---|---|---|
| VB5/6 P-Code | Up to 85% | Unsupported or ambiguous instructions, lost names and types, and fragments that must be corrected manually. |
| VB5/6 Native Code | Up to 80% | Compiler-generated x86 patterns, optimized expressions, inferred variables, and difficult control flow that require analyst review. |
| C# and VB.NET | Up to 95% | Compiler transformations, unsupported constructs, obfuscation, and project information not stored in the assembly. |
These figures describe typical recovery potential for supported, non-obfuscated applications, not a guarantee for every file. Packers, protection, damaged metadata, unusual controls, obfuscation, and compiler-specific constructs can reduce the result.
What you can recover
VB5/6 interface
Forms, control properties, menus, event relationships, FRX images, icons, and other embedded resources.
.NET code and forms
Supported C# and VB.NET assemblies reconstructed as C# code, plus visual viewing of supported Windows Forms.
Analysis context
Search, references, HEX view, tracing, and analytical reports help a developer understand and repair the unrecovered portion.
AI can improve the reconstruction, but it is still a development task
VB Decompiler includes an AI Helper that sends selected decompiled code through prepared prompts. It can work with a local offline model or through the OpenAI API. AI is useful for explaining unfamiliar fragments, proposing meaningful names, restructuring control flow, and converting analyst-oriented output into cleaner code.
AI cannot verify the missing original intent by itself. Its suggestions must be checked against the disassembly, program behavior, forms, data formats, and surrounding procedures. Think of it as the next recovery step after decompilation, not a promise of automatic recompilation.
Choose the edition by the work you need to do
First compatibility check
Lite is free and needs no registration. It identifies the file, shows VB5/6 P-Code or Native Code disassembly and .NET IL, and recovers the visual part of VB5/6 forms. It does not decompile code.
Source-code recovery
Choose a licensed edition with code decompilation when a developer needs to understand and rebuild lost VB5/6, C#, or VB.NET logic.
Difficult reverse engineering
Tracing, synchronized HEX and disassembly views, search, references, and renaming tools help investigate the portion that static decompilation cannot resolve automatically.
Malware and forensic analysis
Analytic editions add reports that locate file, registry, network, process, and other security-relevant behavior.
Test the actual file before purchasing
Open your legally obtained binary in the free Lite edition first. Then use the Detailed Features chart to choose only the decompilation and analysis capabilities your recovery project requires.