Step 5 Preview hits the AA Pareto frontier with an Intelligence score of 44 and $2.70/M output tokens

Stepfun Step 5 Preview (LLM): On AA Pareto frontier

Stepfun's Step 5 Preview, released September 2026, lands on the Artificial Analysis quality–cost frontier. It scores 44 on the Intelligence Index (rank 25/200), well above the median of 25. Output speed is 100 tokens/sec vs. a 65 average, but the model is verbose—it generated 160M tokens during evaluation, nearly double the 90M median. Pricing is $1.00/M input and $2.70/M output tokens with a 95% cache discount; the full eval cost $918. It accepts text and image inputs and has a 1M-token context window. The post does not disclose parameter count or training details.