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By Jon Lamb · Last updated

Claude vs. Codex for Mendix

Codex with GPT-6 Astra is better for Mendix than Claude Fable 5.1, and it’s not close.

My Mendix comparison. A check marks my pick for each category; both are checked where I consider them equivalent.
CategoryCodexGPT-6 AstraClaudeFable 5.1Notes
Frontier IntelligenceMy pickMy pickBoth are frontier intelligence. Roughly equivalent in my mind.
Computer useMy pick—When the Mendix MCP server chokes on a big page or can’t write a Nanoflow, Codex can use the UI to get it done.
SpeedMy pick—In my experience, there’s less waiting around with Codex, and the whole task generally gets done sooner.
Value for moneyMy pick—My rough impression is that I get about three times as much out of Astra for the same money.
Usage limitsMy pick—OpenAI seems to reset my usage limits all the time. With Claude, a weekly limit feels like an actual weekly limit. There’s even a tracker for the reset announcements.

This is based on my experience using these tools for Mendix. I’ll update this page as the tools change and I have more to compare.