Is GPT-5.6 Luna a good deal?
Whether anything in this catalogue beats GPT-5.6 Luna on both quality and price, and what you give up if it does. A computation on the current catalogue, not an opinion.
12 undominated of 145 · Oct 6, 2026
As of Oct 6, 2026, GLM 5.3 Flash scores higher and costs less than GPT-5.6 Luna for Balanced on LMArena, but it is not a drop-in. You would give up: context, file.
Inspect model evidence Compare differences & requirements
GLM 5.3 Flash scores 38.6 points higher and costs 47% less, but you would give up: context, file.
LMArena Elo · higher is better
Scale starts at 1040 Elo
1431.0
Effective $/M · Balanced · lower is better
$0.450/M
LMArena Elo · higher is better
Scale starts at 1040 Elo
1469.6
Effective $/M · Balanced · lower is better
$0.238/M
GPT-5.6 Luna takes file, image, text, returns up to 128,000 tokens from a 1,050,000-token context, and is listed by 7 sellers.
Compared against 145 rated, priced models on this lens: nothing dominates it outright, 5 more dominate it but give something up. GPT-5.6 Luna scores 1431 at $0.450 per million tokens for this mix.
Higher score, lower price, named losses
Not a drop-in. The loss is why these are not a recommendation.
| Model | LMArena | Effective $/M | You give up |
|---|---|---|---|
| GLM 5.3 Flash | 1469.6 | $0.238/M | context, file |
| DeepSeek V4.1 Flash | 1462.5 | $0.182/M | context, file |
| MiMo-V2.6-Flash | 1456.4 | $0.175/M | file |
| Gemma 4 31B | 1443.4 | $0.205/M | context, max output, file |
| Hy3 | 1440.7 | $0.231/M | context, file, image |
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Constraint: replacements must preserve the model’s capabilities; any losses remain named trade-offs.
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