Step 5 Preview Intelligence, Performance & Price Analysis
Model summary
Step 5 Preview is above average in intelligence, but somewhat expensive when comparing to other open weight models of similar size. It's also notably fast, however somewhat verbose. The model supports text and image input, outputs text, and has a 1M tokens context window.
Step 5 Preview scores 29 on the Artificial Analysis Intelligence Index, placing it above average among comparable models (median: 23). When evaluating the Intelligence Index, it generated 130M tokens, which is somewhat verbose in comparison to the median of 100M.
Pricing for Step 5 Preview is $1.00 per 1M input tokens (somewhat expensive, median: $0.43) and $2.70 per 1M output tokens (somewhat expensive, median: $1.68). On average, it costs $2.35 per task to evaluate Step 5 Preview on the Intelligence Index.
At 146 tokens per second, Step 5 Preview is notably fast (78).
| Reasoning | Yes This page shows the reasoning version of this model. A non-reasoning variant may also exist. |
|---|---|
| Input modality | Supports: text and image |
| Output modality | Supports: text |
| Context window | 1M ~1500 A4 pages of size 12 Arial font |
| Total parameters | 600B |
| Active parameters | 27B Number of parameters active per token during inference |
| License | StepFun Model License 1.0 |
| Model weights | Hugging Face |
Metrics are compared against models of the same class:
- Non-reasoning models → compared only with other non-reasoning models
- Reasoning models → compared across both reasoning and non-reasoning
- Open weights models → compared only with other open weights models of the same size class:
- Tiny: ≤4B parameters
- Small: 4B–40B parameters
- Medium: 40B–150B parameters
- Large: >150B parameters
- Proprietary models → compared across proprietary and open weights models of the same price range, using a blended 3:1 input/output price ratio:
- <$0.15 per 1M tokens
- $0.15–$1 per 1M tokens
- >$1 per 1M tokens
Intelligence
Artificial Analysis Intelligence Index
Artificial Analysis Intelligence Index by Open Weights / Proprietary
Intelligence Index vs. Cost per Task
Measures the performance of models on specific capabilities and industries
Artificial Analysis Finance & Accounting Index
Evaluations
Agentic knowledge work, Elo
Knowledge
1 - hallucination rate
Agentic SaaS workflows
Agentic scientific research workflows in a terminal
Agentic software engineering in open-source repositories
Reasoning & knowledge
Professional document reasoning, All-pass
Agentic coding & terminal use
Physics reasoning
Quantitative analysis on spreadsheets & documents
Legal agentic work, Hallucination-Gated All-Pass Rate
Agentic business operations
Agentic real-world work tasks, Elo
Agentic interactive 3D experiences, Elo
Product and brand videos designed in code, Elo
Kubernetes incident root-cause analysis
Medical long context reasoning
Visual reasoning
Rich, varied, well-crafted language
Well-structured, scannable, answer-first
Truthful, acknowledges uncertainty, non-sycophantic
Use of filler and generic language
AA-Briefcase v1.1
AA-Briefcase Elo
AA-Omniscience v1.1
AA-Omniscience Net Score
AA-PersonalityBench
Personality Indexes
Openness Index
Artificial Analysis Openness Index: Score
Intelligence Index Comparisons
Intelligence Index vs. Cost per Task
Token Use
Output Tokens per Intelligence Index Task
Cost
Cost per Intelligence Index Task
Cost to Run Artificial Analysis Intelligence Index
Pricing: Cache Hit, Input, and Output
Context Window
Context Window
Speed
Measured by Output Speed (tokens per second)
Output Speed
Time per Intelligence Index Task
Latency
Measured by Time (seconds) to First Token
Latency: Time To First Answer Token
End-to-End Response Time
Seconds to output 500 tokens, calculated based on time to first token, 'thinking' time for reasoning models, and output speed
End-to-End Response Time
Model Size (Open Weights Models Only)
Model Size: Total and Active Parameters
Frequently Asked Questions
Common questions about Step 5 Preview
Step 5 Preview was released on September 18, 2026.
Step 5 Preview was created by StepFun.
Step 5 Preview scores 29 on the Artificial Analysis Intelligence Index, placing it above average among other open weight models of similar size (median: 23).
Step 5 Preview generates output at 145.8 tokens per second (based on StepFun's API), which is well above average compared to other open weight models of similar size (median: 77.8 t/s).
Step 5 Preview has a time to first token (TTFT) of 0.88s (based on StepFun's API), which is very competitive compared to other open weight models of similar size (median: 1.56s).
Step 5 Preview costs $1.00 per 1M input tokens (somewhat higher than average, median: $0.43) and $2.70 per 1M output tokens (somewhat higher than average, median: $1.68), based on StepFun's API.
Step 5 Preview costs $1.00 per 1M input tokens and $2.70 per 1M output tokens (based on StepFun's API). For a blended rate (7:2:1 cache hit/input/output ratio), this is $0.54 per 1M tokens. Pricing may vary by provider. Compare provider pricing
When evaluated on the Intelligence Index, Step 5 Preview generated 130M output tokens, which is somewhat higher than average compared to other open weight models of similar size (median: 100M).
Yes, Step 5 Preview is a reasoning model. It uses extended thinking or chain-of-thought reasoning to work through complex problems before providing an answer.
Step 5 Preview supports text and image input.
Step 5 Preview supports text output.
Yes, Step 5 Preview supports image input and can analyze, describe, and answer questions about images.
Yes, Step 5 Preview is multimodal. It can process text and image input and generate text output.
Step 5 Preview has a context window of 1.0M tokens. This determines how much text and conversation history the model can process in a single request.
Yes, Step 5 Preview is open weights. The model weights are publicly available and can be downloaded for self-hosting.
Step 5 Preview has 600 billion parameters (27 billion active).
Step 5 Preview is a Mixture of Experts (MoE) model with 600 billion total parameters, but only 27 billion active parameters are used during inference.
Step 5 Preview is released under the StepFun Model License 1.0 license. Commercial use is allowed with restrictions. View license
Step 5 Preview achieves a score of 29 on the Artificial Analysis Intelligence Index. This composite benchmark evaluates models across knowledge work, coding, science, and general knowledge.
Yes, Step 5 Preview is available via API through 1 provider. Compare API providers
Step 5 Preview is available through 1 API provider. Compare providers