GPT-5.6 Sol
ECI#6
162GPT-5.6 Sol is a closed-weights model from OpenAI, released July 9, 2026. It has an ECI score of 162 and ranks 6th of 249 tracked models. At the time of its release, it ranked 3rd of 230 tracked models. At $2/Mtok for input tokens and $10/Mtok for output tokens, it is less expensive per token than similarly-capable models.
Input price$2 / 1M tokens
Output price$10 / 1M tokens
ParametersUnknown
Training computeUnknown
GPT-5.6 Sol vs select alternatives
Reasoning
| Domain | Benchmark | GPT-5.6 Sol | |||
|---|---|---|---|---|---|
ECI scoreBest score 166 | 162 | 162 | 163 | 155 | |
| Ranking | #6 | #5 | #3 | #27 | |
| Games | Chess PuzzlesBest score 72.0% | ||||
Earthborne Rangers (EBR-bench)Best score 76.2% | |||||
Mystery Game PuzzlesBest score 84.0% | |||||
| Mathematics | FrontierMath ErdősBest score 2.9% | ||||
FrontierMath Tiers 1-3 (v2)Best score 93.7% | |||||
FrontierMath Tier 4 (v2)Best score 97.6% | |||||
| Science | GPQA DiamondBest score 95.8% | ||||
| Software engineering | MirrorCodeBest score 73.3% | ||||
| World knowledge | SimpleQA VerifiedBest score 75.6% |
