Last Updated on 2 November 2025 by Roberto De Pedrini
Index
👉 Review: Bob Cozzi’s RPG IV to RPG Free Conversion – a useful VS Code extension for RPG modernization
If you’re working on RPG modernization projects, this extension by Bob Cozzi (Cozzi Research) might save you a lot of time and manual effort.
The extension, available on the Visual Studio Code Marketplace, allows you to convert fixed-format RPG IV code to free-format RPG directly inside VS Code.
đź”— Download from VS Code Marketplace
đź§ What it does
The RPG IV to RPG Free Format Conversion extension lets you highlight a block of fixed-format RPG code – or even an entire program – and simply choose the command “Convert RPG IV to Free Format.”
According to the documentation, it supports:
- Header (H), File (F), Definition (D), and most Calculation (C) specifications
- Partial conversion of embedded SQL statements
- Optional editing helpers for fixed-format RPG such as Smart Tab and Smart Enter to improve code readability and navigation
In short: it’s a simple and practical tool for developers who are still maintaining legacy RPG applications but want to start moving toward the modern free-format style.
⚙️ Why it’s useful for modernization projects
After testing it, here are the key takeaways:
✅ Speed – you can instantly convert sections of code without rewriting everything manually.
✅ Practicality – perfect when working on multiple RPG programs during a modernization project, allowing incremental updates instead of full rewrites.
✅ Compatibility – works well with mixed codebases that contain both legacy and free-format sections.
✅ Editing improvements – the included smart-editing features also make maintaining old fixed-format code more pleasant.
⚠️ What to keep in mind
While very handy, this isn’t a complete refactoring tool. Some important considerations:
- It doesn’t perform deep code restructuring or logical refactoring. The author explicitly states that it’s not designed to handle RPG II cycle code or automatically manage complex I/O specifications.
- Not all C-specs are fully converted yet – some cases may require manual adjustment after conversion.
- In complex environments, the generated free-format code should always be reviewed, tested, and integrated carefully into your build / debug pipelines.
- It doesn’t automatically transform very old cycle or indicator-based logic – those cases still require developer attention.
So – it’s a great accelerator, but not a “one-click modernization” solution.
đź’ˇ How to use it effectively
Some practical tips for getting the most out of the extension:
- Work on a backup of your source or in a test environment.
- Identify code sections (H, F, D, C specs) that are good candidates for conversion.
- When selecting logic blocks (IF/ELSE/WHEN/CASxx), be sure to include the entire structure – the converter relies on proper selection context.
- After conversion, compile and test the output code to ensure correct syntax and logic.
- Explore the extension settings (
rpgiv2free.removeFREEDirective, etc.) to customize conversion output to your internal standards. - Plan a progressive modernization approach – convert and test gradually, integrating new free-format code step by step.
đź§ Final thoughts
Bob Cozzi’s RPG IV to Free Format extension is a solid and practical tool that can accelerate the modernization of RPG applications on IBM i.
It simplifies one of the most tedious parts of the modernization process – syntax conversion – while leaving the developer in full control of the logic.
It’s not meant to replace a full modernization framework or code-refactoring suite, but it’s an excellent companion tool to have in your toolkit.
For anyone maintaining legacy RPG code, this is definitely worth trying — especially if you’re working in VS Code and want a lighter, more modern development experience.
🔗 Download on Visual Studio Marketplace – Cozzi Research RPG IV to Free Format Converter
RPG Fixed to Free conversion example:



