# Claude Haiku Versus GPT-Luna

> Source: <https://www.dotnetperls.com/2026_10_11_claude-haiku-versus-gpt-6-luna>
> Published: 2026-10-11 07:00:00+00:00

As regular readers of this blog will know, I have been using **Claude Haiku 5.5** and **GPT-6-Luna** on **OpenRouter** to generate **Rust code**. Most of the time, code generation costs less than $0.01 (often as low as $0.005) with both of these models, so they are economical assuming you use them only a few times a day.

Both models also seem to respond with the generated content in **10-30 seconds**, so they are very similar overall. I have noticed Claude Haiku has a little **different style** of Rust code it generates—it tends to prefer separate functions, while GPT-6-Luna puts more things in a single function.

As far as functionality goes, the **code usually works** on my **first attempt** in both models. Sometimes Haiku or Luna will write code that does not fit my needs correctly. Usually a more advanced model like Opus or Sol will generate correct code in these cases.

So the **comparison** results: both of these "cheap" models occasionally make **mistakes**, but they are often **good enough**, and if one fails, try the other. As far as when to use Haiku and Luna—I would recommend using them **first** on all code generation, and only if the result is incorrect, using a more expensive model.