Home / Compare / Gemma 4 31B vs GPT-6 Luna

Gemma 4 31B vs GPT-6 Luna

For a typical chat reply (2,000 tokens in, 400 out), GPT-6 Luna costs 1.3× as much as Gemma 4 31B: $0.40 against $0.316 per 1,000 requests at list price on 2026-09-28.

Gemma 4 31BGPT-6 Luna
Input, per 1M tokens$0.09$0.10
Output, per 1M tokens$0.34$0.50
Context window262K1.05M
Classification or routing (600 tokens in, 10 out), per 1,000$0.0574$0.065
Chat reply (2,000 in, 400 out), per 1,000$0.316$0.40
Retrieval-augmented answer (8,000 in, 500 out), per 1,000$0.89$1.05
Confidence signalyesno
Tool callingyesyes
BANKING77, correct of 400304320

Which one should carry your traffic?

If Gemma 4 31B answers your requests as well as GPT-6 Luna, moving that traffic saves 21% on chat-shaped requests. Averages cannot tell you whether it does for your requests. Gemma 4 31B exposes a confidence signal, so Gimbix can let it answer first and hand unsure cases to GPT-6 Luna.

Gemma 4 31B profile · GPT-6 Luna profile · Measure it on your traffic