
StepFun API
situationalAPI for Step-2/Step-3 family of frontier MoE models from Shanghai.
Visit platform.stepfun.com →> **StepFun API** — situational > Verified 2026-08-24 > Limitation: The hosted API is proprietary; Step 3.5 Flash and Step 3.7 Flash weights are separate open-weight releases. > > https://noemium.com/tools/stepfun-api/Add to kitOpen in NoemiumFact-check this catalog entry for StepFun API (models-api). Verdict: situational Verdict text: Step 3.7 Flash is cheap, open weights, and scores well on coding and math benchmarks. Step-2 is a capable closed model at mid-tier prices. Brand recognition and docs outside China are weak, and access often runs through resellers. Limitations: - The hosted API is proprietary; Step 3.5 Flash and Step 3.7 Flash weights are separate open-weight releases. - StepFun runs separate China (platform.stepfun.com) and global (platform.stepfun.ai) platforms with non-interchangeable API keys. - Lower Western brand recognition; docs mostly Chinese. - Mixed access outside China; often reached via resellers. - Step-2 is closed, unlike Step 3.5 Flash and Step 3.7 Flash. - Smaller model family than Qwen or Tencent. Receipts: https://platform.stepfun.ai https://github.com/stepfun-ai/Step-3.7-Flash https://apirank.vip/zh/tutorials/stepfun-api-review/ https://tokenmix.ai/blog/step-3-5-flash-review-stepfun-2026 Last verified: 2026-08-24 Find outdated prices, wrong claims, or missing limitations. Cite primary sources (docs, pricing pages, benchmarks, model cards). Do not use marketing pages.[](https://noemium.com/tools/stepfun-api/)
ledger entry · observed by @whysanesanders
Step 3.7 Flash is cheap, open weights, and scores well on coding and math benchmarks. Step-2 is a capable closed model at mid-tier prices. Brand recognition and docs outside China are weak, and access often runs through resellers.
Strengths
- Step 3.7 Flash is cheap, open weights, and strong on coding and math.
- Step-2 is a capable closed model at mid-tier prices.
- The family covers text, vision, and reasoning variants.
Known limitations
- The hosted API is proprietary; Step 3.5 Flash and Step 3.7 Flash weights are separate open-weight releases.
- StepFun runs separate China (platform.stepfun.com) and global (platform.stepfun.ai) platforms with non-interchangeable API keys.
- Lower Western brand recognition; docs mostly Chinese.
- Mixed access outside China; often reached via resellers.
- Step-2 is closed, unlike Step 3.5 Flash and Step 3.7 Flash.
- Smaller model family than Qwen or Tencent.
Use it when
- Cost-sensitive coding and math workloads that fit the Flash SKUs.
- Teams that want Step-2's closed-model quality without premium pricing.
Skip it when
- You need strong Western brand recognition and English-first docs.
- You want one API key that works across China and global platforms.
- You need a model family as broad as Qwen or Tencent.
Buy-check
- ·Price — paid, Step 3.7 Flash ~$0.20/$1.15 per 1M; Step 3.5 Flash open-source $0.10/$0.30; Step-2 ~$0.83/$2.50; Step-2-mini ~$0.14/$0.42; Step-1.5V ~$0.42/$1.25; Step-R ~$1.11/$3.33 as of 2026-08-24. Open the pricing page, not a screenshot.
- ·Free tier — Free tier exists — burn it first.
- ·Cancel fallout — What happens to your data/projects on cancel — check the ToS, not the FAQ.
- ·Seat math — Per-seat pricing multiplies quietly. Count seats before the annual plan.
- ·Who skips it — Also skipped when: You need strong Western brand recognition and English-first docs.; You want one API key that works across China and global platforms..
Price trail — 1 revisionchangelog →
- 2026-W34Step-2 ~$0.83/$2.50 per 1M; Step-2-mini ~$0.14/$0.42;…Step 3.7 Flash ~$0.20/$1.15 per 1M; Step 3.5 Flash op…
Facts
- pricing
- paid1
- price note
- Step 3.7 Flash ~$0.20/$1.15 per 1M; Step 3.5 Flash open-source $0.10/$0.30; Step-2 ~$0.83/$2.50; Step-2-mini ~$0.14/$0.42; Step-1.5V ~$0.42/$1.25; Step-R ~$1.11/$3.33
- free tier
- yes — paid to keep using
- open source
- no
- api
- yes
- self-host
- no
- category
- models-api
- evidence
- source-verified
- Models
- locked
Sources
- 1platform.stepfun.ai[snapshot]
- 2github.com/stepfun-ai/Step-3.7-Flash[snapshot]
- 3apirank.vip/zh/tutorials/stepfun-api-review/[snapshot]
- 4tokenmix.ai/blog/step-3-5-flash-review-stepfun-2026[snapshot]
No source, no number.
Similar joball alternatives →
| tool | verdict | price | oss | self-host |
|---|---|---|---|---|
| StepFun API | situational | paid | no | no |
| Google AI Studio / Gemini API | ship | freemium | no | no |
| Anthropic API | ship | paid | no | no |
| Cerebras | ship | freemium | no | no |
Facts from the catalog files — not scores you can buy. Quality and speed stay in the briefing, not in a fake 1–5 grid.
Google AI Studio / Gemini API
Gemini API with a real free tier — huge context, multimodal, generous limits.
APIFREE TIER
freemiumfree tier (text models); paid from $0.75/1M input (Gemini 3.7 Flash promo till 2027-01)
Anthropic API
Claude models direct — the practitioner's pick for coding and long-form text.
API
paidpay-as-you-go, from $1/1M input (Haiku 4.5); small free credits for new users
Cerebras
Ultra-fast inference on wafer-scale AI accelerators with competitive API pricing.
APIFREE TIER
freemiumfree trial ($5 credits); self-serve Developer from $10 deposit; Enterprise custom