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StepFun vs Upstage: Token Pricing, Speed & Intelligence

Full comparison of StepFun and Upstage — live token pricing, latency, throughput, context window, strengths, weaknesses, and best use cases. Rates sourced from public APIs — verify before use.

StepFun

Step-5 — Chinese frontier LLM with strong multimodal and reasoning capability

StepFun is a Chinese AI startup developing the Step model series. Step-5 Preview is the frontier tier, competing with top Chinese and international models on reasoning and multimodal benchmarks. Step-3.7 Flash is the efficient tier for cost-sensitive workloads. StepFun is backed by Tencent and focuses on enterprise and developer API access.

ReasoningChinese NLPMultimodal tasksCost-sensitive inference
Proprietary models

Upstage

Solar Pro 4, Solar Pro 3, Solar Pro 2 — Korean frontier models with strong multilingual performance

Upstage is a Korean AI company offering the Solar model family via API. Solar Pro 4 is the current flagship, with Solar Pro 3 and Solar Pro 2 available at lower price points. The Solar models are known for strong multilingual performance, particularly in Korean and English, and competitive pricing relative to their capability tier. Pricing is published at upstage.ai/pricing.

ChatMultilingualKorean NLPCost-efficiencyEnterprise
Proprietary models

Key metric comparison

Cheapest input ($/1M)

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Cheapest output ($/1M)

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Peak throughput

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Best latency (TTFT)

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Intelligence score

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Context window

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Live token pricing

Strengths and weaknesses

StepFun

Step-5 Preview is competitive with top Chinese frontier models on reasoning benchmarks
Step-3.7 Flash at $0.20/$1.15 per 1M tokens offers strong value for efficient inference
Multimodal capability on Step-5 (text, image, video understanding)
Backed by Tencent with enterprise-grade infrastructure
Newer entrant — smaller track record than established frontier labs
Documentation and support primarily in Chinese
Limited international ecosystem and third-party integrations

Upstage

Solar Pro 4: competitive frontier-tier pricing at $0.30/$1.20 per 1M tokens
Strong multilingual performance — Korean and English
Three-tier model family: Solar Pro 4, 3, and 2 for different cost/quality trade-offs
OpenAI-compatible API
Smaller global ecosystem than OpenAI or Anthropic
Limited model variety beyond the Solar family
Less documentation in English than major US providers

Key differentiators

StepFun

Step-5 is StepFun's frontier reasoning model with multimodal capability, backed by Tencent — positioned as a competitive alternative to Qwen and ERNIE for Chinese enterprise workloads.

Upstage

Korean-built Solar models with strong multilingual performance and competitive frontier-tier pricing — Solar Pro 4 at $0.30/$1.20 per 1M tokens.

Frequently asked questions

StepFun FAQs

What is StepFun?

StepFun is a Chinese AI startup backed by Tencent, developing the Step model series. Step-5 Preview is the frontier tier and Step-3.7 Flash is the efficient tier, both available via the StepFun API.

How much does the StepFun API cost?

Step-5 Preview is $1.00/$2.70 per 1M input/output tokens. Step-3.7 Flash is $0.20/$1.15 per 1M tokens. See platform.stepfun.com/docs/pricing for current rates.

Does Step-5 support multimodal input?

Yes. Step-5 Preview supports text, image, and video understanding in a single API call, making it suitable for multimodal enterprise applications.

Upstage FAQs

What is Upstage Solar?

Upstage Solar is a family of LLMs from Korean AI company Upstage. Solar Pro 4 is the current flagship, with Solar Pro 3 and Solar Pro 2 at lower price points. See upstage.ai/pricing for current rates.

How much does Upstage Solar cost?

As of October 2026: Solar Pro 4 $0.30/$1.20 per 1M tokens, Solar Pro 3 $0.15/$0.60, Solar Pro 2 $0.15/$0.60. See upstage.ai/pricing for current rates.

Is Upstage good for Korean language tasks?

Yes. The Solar model family is developed by a Korean AI company and shows strong performance on Korean-language benchmarks, making it a top choice for Korean NLP workloads.

Provider resources

StepFun — Step-5 — Chinese frontier LLM with strong multimodal and reasoning capability

StepFun is a Chinese AI startup developing the Step model series. Step-5 Preview is the frontier tier, competing with top Chinese and international models on reasoning and multimodal benchmarks. Step-3.7 Flash is the efficient tier for cost-sensitive workloads. StepFun is backed by Tencent and focuses on enterprise and developer API access.

Step-5 is StepFun's frontier reasoning model with multimodal capability, backed by Tencent — positioned as a competitive alternative to Qwen and ERNIE for Chinese enterprise workloads.

Upstage — Solar Pro 4, Solar Pro 3, Solar Pro 2 — Korean frontier models with strong multilingual performance

Upstage is a Korean AI company offering the Solar model family via API. Solar Pro 4 is the current flagship, with Solar Pro 3 and Solar Pro 2 available at lower price points. The Solar models are known for strong multilingual performance, particularly in Korean and English, and competitive pricing relative to their capability tier. Pricing is published at upstage.ai/pricing.

Korean-built Solar models with strong multilingual performance and competitive frontier-tier pricing — Solar Pro 4 at $0.30/$1.20 per 1M tokens.

Key strengths compared

StepFun

  • Step-5 Preview is competitive with top Chinese frontier models on reasoning benchmarks
  • Step-3.7 Flash at $0.20/$1.15 per 1M tokens offers strong value for efficient inference
  • Multimodal capability on Step-5 (text, image, video understanding)
  • Newer entrant — smaller track record than established frontier labs
  • Documentation and support primarily in Chinese

Upstage

  • Solar Pro 4: competitive frontier-tier pricing at $0.30/$1.20 per 1M tokens
  • Strong multilingual performance — Korean and English
  • Three-tier model family: Solar Pro 4, 3, and 2 for different cost/quality trade-offs
  • Smaller global ecosystem than OpenAI or Anthropic
  • Limited model variety beyond the Solar family

Key weaknesses compared

StepFun

  • Newer entrant — smaller track record than established frontier labs
  • Documentation and support primarily in Chinese
  • Limited international ecosystem and third-party integrations

Upstage

  • Smaller global ecosystem than OpenAI or Anthropic
  • Limited model variety beyond the Solar family
  • Less documentation in English than major US providers

Provider category context

StepFun is a frontier lab, founded in 2023. Upstage is a frontier lab, founded in 2020. Both are frontier lab providers — the comparison is primarily about pricing, model selection, and feature differentiation within the same tier.

How to choose between them

Both StepFun and Upstage are frontier labs with proprietary models. Choose based on benchmark performance for your specific task: StepFun leads on step-5 preview is competitive with top chinese frontier models on reasoning benchmarks, while Upstage leads on solar pro 4: competitive frontier-tier pricing at $0.30/$1.20 per 1m tokens. For cost-sensitive workloads, compare the cheapest model tier from each provider in the pricing table above — the gap between efficient-tier models is often larger than between flagship models.