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GPT-5 Pro vs Step-3.5-Flash
Comprehensive side-by-side LLM comparison
GPT-5 Pro supports multimodal inputs. Both models have their strengths depending on your specific coding needs.
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OpenAI
GPT-5 Pro is an extended-reasoning variant from the GPT-5 family that applies more compute per response for deeper, more thorough answers on complex problems. It features the same 400K token context window and multimodal capabilities as GPT-5, with additional reasoning depth suited to research-grade analysis, advanced coding, and tasks requiring comprehensive, accurate outputs.
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StepFun
Step-3.5-Flash, released by StepFun on February 2, 2026, is a Mixture-of-Experts large language model with 197 billion total parameters and approximately 11 billion active parameters per inference. It features a 256K token context window using a 3:1 sliding-window-to-full-attention ratio, processing 100–350 tokens per second. Step-3.5-Flash targets agentic tasks, coding workflows, and open-source deployments requiring frontier reasoning capabilities with efficient inference, under an Apache 2.0 license.
5 months newer
GPT-5 Pro
OpenAI
2025-08-07
Step-3.5-Flash
StepFun
2026-02-02
Provider Availability & Performance
Available providers and their performance metrics
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GPT-5 Pro
0 providers
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Step-3.5-Flash
0 providers
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GPT-5 Pro
Avg Score:0.0%
Providers:0
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Step-3.5-Flash
Avg Score:0.0%
Providers:0