StepFun · Released Oct 8, 2026
Step 5 Preview
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...
- Top 11%SciCode
- Top 19%CritPt
- Top 33%WebDev Arena
- Released
- Oct 8 2026
- Context window
- 1M 64K out
- Input / 1M tokens
- $1.00 from Free
- Output / 1M tokens
- $2.70 from Free
Where to run it
19 providers compared
Free to try on Nvidia, OpenCode — free endpoints are often limited-time and rate-limited. Included in OpenCode Go. Cheapest: InferenceNet, DeepInfra, StepFun +10 more at $1.00 / $2.70 per 1M input / output tokens — 27% less than the priciest option.
| Provider | Input | Output | Cache read | Context | Max output | Uptime | vs. best |
|---|---|---|---|---|---|---|---|
| Nvidiafree · may be limited-time | Free | Free | — | 1M | 1M | — | Free |
| OpenCodefree · may be limited-time | Free | Free | Free | 1M | 66K | — | Free |
| OpenCode Gosubscription plan | Plan | Plan | Plan | 1M | 66K | — | Plan |
| InferenceNetus · FP4 | $1.00 | $2.70 | $0.05 | 1M | 131K | 100%24h | Cheapest |
| InferenceNetFP4 | $1.00 | $2.70 | $0.05 | 1M | 131K | 100%24h | Cheapest |
| DeepInfraFP8 | $1.00 | $2.70 | $0.10 | 1M | 66K | 100%24h | Cheapest |
| StepFunFP8 | $1.00 | $2.70 | $0.10 | 1M | 64K | 98.5%24h | Cheapest |
| FeatherlessFP4 | $1.00 | $2.70 | $0.10 | 262K | 33K | 37.7%24h | Cheapest |
| NanoGPT | $1.00 | $2.70 | $0.05 | 1M | 1M | — | Cheapest |
| Kilo Gateway | $1.00 | $2.70 | $0.10 | 1M | 64K | — | Cheapest |
| Vercel AI Gatewayno tool calling | $1.00 | $2.70 | $0.10 | 1M | 1M | — | Cheapest |
| Requesty | $1.00 | $2.70 | $0.05 | 1M | 66K | — | Cheapest |
| Novita AI | $1.00 | $2.70 | $0.10 | 1M | 64K | — | Cheapest |
| CommandCode | $1.00 | $2.70 | $0.05 | 1M | 1M | — | Cheapest |
| StepFun (Global) | $1.00 | $2.70 | $0.10 | 1.02M | 66K | — | Cheapest |
| EmpirioLabs AI | $1.00 | $2.70 | $0.05 | 1.02M | 131K | — | Cheapest |
| Eden AI | $1.00 | $2.70 | $0.05 | 1M | 1M | — | Cheapest |
| StepFun (China) | $1.05 | $2.99 | $0.10 | 1M | 66K | — | +7% |
| AIHubMix | $1.08 | $3.09 | $0.054 | 1M | 64K | — | +11% |
| AI/ML API | $1.38 | $3.71 | $0.069 | 1M | 64K | — | +38% |
Value
Price vs. performance
Step 5 Preview Other StepFun Other labs Value frontier · SciCode vs. input price per 1M tokens (log scale) · Drag to pan, pinch or Ctrl + scroll to zoom, double-click to zoom in.
Benchmarks
4 benchmark scores
| Benchmark | Score | Rank | Leader |
|---|---|---|---|
| SciCodeSoftware engineering · Research-coding problems from the natural sciences | 58.9% | #11of 102 | Claude Opus 5.566.9% |
| WebDev ArenaDesign & visual · People vote on which model builds the better website (Elo) | 1570 | #29of 90 | Claude Opus 5.51820 |
| CritPtReasoning & knowledge · Open-ended, research-level physics problems | 20.9% | #20of 111 | GPT-5.6 Sol32.3% |
| ProofBenchMaths · Graduate maths proofs verified in Lean 4 | 42.0% | #39of 70 | Claude Sonnet 5.5100.0% |
Specs
Details
- Model ID
stepfun/step-5-preview- Developer
- StepFun
- Release date
- Oct 8, 2026 ·
- Context window
- 1,048,576 tokens
- Max output
- 64,000 tokens
- API price
- $1.00 / $2.70 per 1M input / output tokens
- Providers
- 19
- Input types
- text, image, video
- Reasoning
- Yes
- Tool calling
- Yes
- Open weights
- Yes
- Free tier
- No
Release date and prices from OpenRouter's catalog; providers from OpenRouter and models.dev. Buying directly from a provider can cost a little differently. Speed, latency and uptime are measured on OpenRouter only; uptime is the share of OpenRouter requests each provider served over the last day. Benchmark scores are the best result per benchmark from Epoch AI, licensed CC BY 4.0. Rank counts every model tracked here with a score.