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GPT 5.6 Terra vs GPT 6 Luna

Both are SOTA right now. Each row below is one board’s call on the two, and the marked figure is the one that board places higher. No row is added to another, so there is no overall winner: the boards measure different things, and where they split, that is the finding.

Board GPT 5.6 Terra GPT 6 Luna
Artificial Analysis LLM Leaderboard Artificial Analysis Intelligence Index 42.1 No. 19 of 372 38.1 No. 32 of 372
Arena — Agent Overall 0.004 No. 32 of 49 0.014 No. 25 of 49
Artificial Analysis Coding Agents Artificial Analysis Coding Agent Index — 0.411 No. 21 of 22
Arena — Code Overall 1519 No. 46 of 109 1579 No. 32 of 109
Arena — Text Overall (style control) 1465 No. 51 of 306 1443 No. 90 of 306
Arena — Vision Overall (style control) 1268 No. 36 of 128 —

Each rank is the board’s own: the rank it publishes, or its place in its own order where it publishes none. The bar is how much of that board the model is ahead of. Scores from different boards cannot be compared.

At a glance

Developer OpenAI OpenAI
Weights closed closed
Released 2026-07-09—
Price Blended Price, USD per 1M tokens (3:1 input:output) $4.50$0.20
Value: where it sits on the kill line SOTA SOTA

GPT 5.6 Terra →GPT 6 Luna → How the kill line is drawn →

GPT 5.6 Terra against the other SOTA models

GPT 6 Luna against the other SOTA models