Grok Code Fast 1 vs StepFun Step-2
Grok Code Fast 1 (2025) and StepFun Step-2 (2025) are agentic coding models from xAI and StepFun. Grok Code Fast 1 ships a 262K-token context window, while StepFun Step-2 ships a 128k-token context window. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing. The goal is to make the tradeoff clear before deeper testing.
StepFun Step-2 is safer overall; choose Grok Code Fast 1 when coding workflow support matters.
Specs
| Released | 2025-08-27 | 2025-10-15 |
| Context window | 262K | 128k |
| Parameters | 314B | — |
| Architecture | mixture of experts | - |
| License | Proprietary | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| Grok Code Fast 1 | StepFun Step-2 | |
|---|---|---|
| Input price | $0.2/1M tokens | - |
| Output price | $1.5/1M tokens | - |
| Providers | - |
Capabilities
| Grok Code Fast 1 | StepFun Step-2 | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on function calling: Grok Code Fast 1, tool use: Grok Code Fast 1, and structured outputs: Grok Code Fast 1. Both models share the core language-model surface, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: Grok Code Fast 1 has $0.2/1M input tokens and StepFun Step-2 has no token price sourced yet. Provider availability is 1 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Grok Code Fast 1 when coding workflow support, larger context windows, and broader provider choice are central to the workload. Choose StepFun Step-2 when provider fit are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, Grok Code Fast 1 or StepFun Step-2?
Grok Code Fast 1 supports 262K tokens, while StepFun Step-2 supports 128k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Grok Code Fast 1 or StepFun Step-2 open source?
Grok Code Fast 1 is listed under Proprietary. StepFun Step-2 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for function calling, Grok Code Fast 1 or StepFun Step-2?
Grok Code Fast 1 has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for tool use, Grok Code Fast 1 or StepFun Step-2?
Grok Code Fast 1 has the clearer documented tool use signal in this comparison. If tool use is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for structured outputs, Grok Code Fast 1 or StepFun Step-2?
Grok Code Fast 1 has the clearer documented structured outputs signal in this comparison. If structured outputs is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Grok Code Fast 1 and StepFun Step-2?
Grok Code Fast 1 is available on OpenRouter. StepFun Step-2 is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.