gpt-oss-120b
ECI#109
140gpt-oss-120b is an open-weights model from OpenAI, released August 5, 2025. It has an ECI score of 140 and ranks 109th of 249 tracked models. At the time of its release, it ranked 20th of 156 tracked models. At $0.10/Mtok for input tokens and $0.55/Mtok for output tokens, it is less expensive per token than similarly-capable models.
Input price$0.10 / 1M tokens
Output price$0.55 / 1M tokens
Parameters1.2e11
Training compute4.9e24 FLOP
gpt-oss-120b vs select alternatives
Reasoning
| Domain | Benchmark | gpt-oss-120b | |||
|---|---|---|---|---|---|
ECI scoreBest score 166 | 140 | 137 | 140 | 142 | |
| Ranking | #109 | #125 | #107 | #95 | |
| Agent | Vending-Bench 2Best score 11181.9 | -21.5 | — | — | 71.6 |
| Conceptual reasoning | SimpleBenchBest score 81.9% | ||||
| Games | Chess PuzzlesBest score 72.0% | ||||
Mystery Game PuzzlesBest score 84.0% | |||||
| Mathematics | OTIS Mock AIME 2024-2025Best score 100.0% | ||||
| Science | SciCodeBest score 62.0% | ||||
GPQA DiamondBest score 95.8% | |||||
| Software engineering | Aider PolyglotBest score 88.0% | ||||
WeirdML (v2)Best score 92.9% |
