OpenAI just dropped its GPT-5.6 model family, and the flagship Sol variant is already climbing the leaderboards. According to independent evaluations from Artificial Analysis, Sol ranks second in the Intelligence Index, trailing only Anthropic’s Claude Fable 5, while simultaneously claiming the top spot in the Coding Agent Index.
The kicker: it does this at roughly a third of what Claude Fable 5 charges.
The numbers behind Sol’s rise
Sol scored 88.8% on Terminal-Bench 2.1 in standard mode. In its “Ultra” configuration, which deploys multiple sub-agents working in concert, that number jumps to 91.9%.
On the pricing side, Sol comes in at $5 per million input tokens and $30 per million output tokens. Claude Fable 5, its closest competitor in the intelligence rankings, charges $10 input and $50 output per million tokens.
