4gl Form Decompiler

Because the reconstruction process is best appreciated by seeing the results firsthand, it can be difficult to demonstrate effectively with a simple example or screenshot alone. The easiest way to understand what the tool can do is to upload a form and let it process it for you.

Simply upload an Informix 4GL compiled form binary (.frm) file, and the tool will analyze the binary structure and reconstruct the original .per source definition. The decompiler is designed to recover the form layout, field definitions, attributes, and other information contained within the compiled form, making it easier to inspect, document, maintain, or migrate legacy applications when the original source is no longer available.

Single-file uploads are supported, and once processing is complete, the reconstructed .per source is rendered directly on the page for immediate review. No additional software, configuration, or manual extraction steps are required.

The decompiler is validated against a regression corpus of 729 real‑world compiled 4GL forms drawn from production applications. Every form in that corpus round‑trips byte‑for‑byte: the reconstructed .per source, when recompiled, produces a form binary identical to the original — a 100% byte‑exact reconstruction rate across the entire test set, spanning the full range of field types, attributes, INCLUDE lists, screen records and screen arrays found in real applications.

The decompiler runs server-side; nothing is stored. For batch or scripted use, see the ondebug CLI.