VBReFormer, the native and P-Code VB decompiler for your VB5 and VB6 applications

VB6 compiles either to P-Code (pseudo-code run by the virtual machine) or to Native Code (x86 machine instructions, the default setting). As of generation 2 (VBReFormer 7), the same engine decompiles both into readable Visual Basic: 1,158 of the 1,164 defined P-Code instructions are translated, a measurement published on the coverage page. The previous generation reconstructed Native Code only.

It interprets. Generation 1 matched patterns in the compiled code and rendered only what it recognised. Generation 2 interprets machine code and P-code alike to reconstruct expressions and types; what it cannot reconstruct is neither dropped nor guessed, it is named and explained in the export notes.

VBReFormer analyses every executable compiled with Visual Basic 5 or 6, in P-Code as well as Native Code. The interface — forms, controls, resources — is extracted in full in every case. Code reconstruction depends on what the binary kept: the free edition shows you that on your own file, before any purchase.

Yes: in practice, about 80% of projects recompile without any touch-up. The export writes the headers the IDE requires (VERSION, Attribute VB_Name), without which VB6 rejects the file. A value that could not be established is never invented: it becomes a call to VBRF_ValeurInconnue(), which VB6 accepts and which you find with a search. What is not in the binary is named and explained in the export notes.

Whatever Visual Basic needs at run time is in the file and comes back: names of forms, classes, modules and controls, event handlers, public class members, interface properties, runtime calls, API declarations. What the compiler threw away cannot be recovered, by any tool: comments, names of local variables and parameters, named constants replaced by their value, and the names of procedures in .bas modules. On average, 90% of the source code is recovered; what is missing comes down to those elements, absent from the file.

That is exactly what the free edition is for: it shows you, on YOUR file and before any purchase, what can be extracted — forms, resources, project structure. We always recommend trying it first. As licenses are digital content delivered immediately, sales are final; if you hit a technical issue, our support will work with you on a solution.

Yes, and without buying anything. The free desktop edition is the same installer as the licensed one: it extracts the full interface (forms, resources, project structure) and shows a preview of the decompiled code, with no time limit. The online studio, served in eleven languages, does the same in the browser with nothing to install: disassembly, P-code, designer, .vbp project and resources are served in full, the reconstructed source code as a preview. The licence unlocks the complete code and the project export.

For the term you choose at purchase: one, two or three years. Email support and every update released during that period are included, at no extra cost. When it expires, access ends and you can take out a new licence. The free edition remains usable with no time limit.

Yes, when you own the rights to the software — the typical case being reconstructing your own lost source code — or within the legal framework of interoperability. You must hold the necessary rights to the analyzed program.

No. VBReFormer handles Visual Basic 5 and 6: .exe, .dll, .ocx and .scr. A .NET assembly needs a .NET decompiler; we compare several on the blog.