GPT-5.4-Cyber vs StepFun Step-2
GPT-5.4-Cyber (2026) and StepFun Step-2 (2025) are frontier reasoning models from OpenAI and StepFun. GPT-5.4-Cyber ships a not-yet-sourced context window, while StepFun Step-2 ships a 128k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads. It focuses on practical selection signals rather than broad model-family marketing.
GPT-5.4-Cyber is safer overall; choose StepFun Step-2 when provider fit matters.
Decision scorecard
Local evidence first| Signal | GPT-5.4-Cyber | StepFun Step-2 |
|---|---|---|
| Best for | reasoning-heavy apps and multimodal apps | general production evaluation |
| Decision fit | Vision | Long context |
| Context window | — | 128k |
| Cheapest output | - | - |
| Provider routes | 0 tracked | 0 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GPT-5.4-Cyber uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags GPT-5.4-Cyber for Vision.
- StepFun Step-2 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags StepFun Step-2 for Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5.4-Cyber
Unavailable
No complete token price in local provider data
StepFun Step-2
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for GPT-5.4-Cyber and StepFun Step-2; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
- No overlapping tracked provider route is sourced for StepFun Step-2 and GPT-5.4-Cyber; plan for SDK, billing, or endpoint changes.
- GPT-5.4-Cyber adds Vision, Multimodal, and Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-14 | 2025-10-15 |
| Context window | — | 128k |
| Parameters | — | 1T (MoE)* |
| Architecture | Decoder Only | - |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-08 | - |
Pricing and availability
| Pricing attribute | GPT-5.4-Cyber | StepFun Step-2 |
|---|---|---|
| Input price | - | - |
| Output price | - | - |
| Providers | - | - |
Pricing not yet sourced for either model.
Capabilities
| Capability | GPT-5.4-Cyber | StepFun Step-2 |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | No |
| JSON / Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.