Step 5 Preview model profile

Profile facts

Profile type

Model research profile

Provider or publisher

StepFun

Context window

1,000,000 tokens

Snapshot date

2026-10-13

Knowledge cutoff

Not disclosed

Reference catalog ID

stepfun/step-5-preview

When to pick Step 5 Preview

Step 5 Preview is a reference profile: StepFun publishes it, Kendr documents it for comparison, and it carries no Kendr alias to call.

Each condition below is derived from this model's own values in the 2026-10-13 snapshot, compared only against models publishing the same field.

• Reach for it when the input includes images. The snapshot records image input, so screenshots, scans, and diagrams can be sent directly instead of described.
• Reach for it when the model has to call tools. Tool calling is recorded in the snapshot, so this route can drive an agent loop rather than only answer in prose.
• Look elsewhere when you need to call it through Kendr today. This is a research reference profile with no Kendr alias. The facts and evidence here are published for comparison; the model is not routable on Kendr.
• Look elsewhere when the request is trivial and latency-sensitive. Reasoning is mandatory on this route and cannot be turned off, so short factual requests still pay reasoning tokens and reasoning latency.
• Look elsewhere when the workload is production traffic. The catalog marks this model preview. Preview routes can change behaviour or availability without the notice a stable route carries.

Context, modalities, and identity

Step 5 Preview accepts text, image, and video and returns text. The snapshot records prompt caching, reasoning controls, structured output, text generation, tool calling, video input, and vision as capabilities or interfaces.

Provider or publisher

StepFun

Context window

1,000,000 tokens

Maximum output

64,000 tokens

Input modalities

text, image, and video

Output modalities

text

Knowledge cutoff

Not disclosed

Model overview

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional knowledge work, with particular strength in finance. It is designed for extended tasks that span large codebases and documents, using tools and refining results over multiple steps.

Reference model ID

stepfun/step-5-preview

Canonical version

stepfun/step-5-preview-20261008

Hugging Face ID

Not separately documented

Capabilities and supported controls

Capabilities and parameters are reported from the dated catalog and source records; their presence does not guarantee identical behavior across every provider route.

Supported parameters

frequency_penalty, include_reasoning, logprobs, max_tokens, reasoning, reasoning_effort, response_format, stop, structured_outputs, temperature, tools, top_logprobs, top_p

• prompt caching
• reasoning controls
• structured output
• text generation
• tool calling
• video input
• vision

Dated pricing snapshot

The dated reference snapshot lists $1 input and $2.7 output per million tokens. Cached input is $0.05 per million tokens.

These are dated third-party reference prices, not Kendr prices or an availability offer. Routes, tiers, caching, region, and provider policy can change the landed price.

Price date

2026-10-13

Input

$1 per 1M tokens

Cached input

$0.05 per 1M tokens

Output

$2.7 per 1M tokens

Provider routes, performance, and uptime

The snapshot retains 1 provider endpoint. Provider prices, context limits, p50 performance, and uptime can differ by route and are not Kendr guarantees.

Active provider endpoints

1

Best p50 latency

3.45 s

Best p50 throughput

80 tok/s

Availability with routing

99.25% over the sampled window

Availability without routing

81.02% over the sampled window

Performance date

2026-10-13

Benchmark evidence and limitations

No comparable third-party benchmark value is present in the 2026-10-13 snapshot. Missing values are not estimated.

Third-party catalog fields normalized from the cited model dataset; benchmark methodology and coverage differ by source.

Popularity and market context

Step 5 Preview ranked #3 in the cited trailing-7-day third-party catalog usage dataset as of 2026-10-13. Observed within the cited trailing-7-day third-party catalog usage dataset; this is not global AI market share.

Third-party catalog rank

#3

Global market share

Not inferred

Observation date

2026-10-13

Frequently asked questions

Sources and evidence dates

1. Step 5 Preview third-party catalog record (catalog, checked 2026-10-13)
2. Third-party model catalog methodology (methodology, checked 2026-10-13)