Compare Claude Sonnet 4.5 Pro from Anthropic and Step 3.7 Flash from StepFun on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.
Claude Sonnet 4.5 Pro
Step 3.7 FlashSonnet 4.5 is the best model in the world for agents, coding, and computer use. It’s also our most accurate and detailed model for long-running tasks, with enhanced domain knowledge in coding, finance, and cybersecurity.
step-3.7-flash is stepfun's flagship inference model, designed for high-complexity tasks that require deep reasoning and fast execution. It excels at decomposing multi-step problems, performing tool calls, and maintaining consistency across massive datasets. It is the preferred choice for complex workloads such as long-context agents, advanced software engineering, and end-to-end research automation.
Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.
Promotional prices show the discounted rate; see each model page for promotion windows.
Daily traffic served through AIHubMix — how demand for each model is trending.
Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.
Estimate your monthly bill for the same workload on each model.
Monthly = daily × 30. Discounted rates applied where a promotion is active.
Step 3.7 Flash: $1.32/M output tokens; Claude Sonnet 4.5 Pro: $240/M. Use the cost calculator above to estimate your own workload.
Claude Sonnet 4.5 Pro accepts text and image input and supports thinking, tool calling, function calling and structured outputs; Step 3.7 Flash accepts text, image and video input.
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