LLM Reference

o4-mini vs Step 3.7 Flash

o4-mini (2025) and Step 3.7 Flash (2026) are frontier-tier reasoning models from OpenAI and StepFun. o4-mini ships a 200k-token context window, while Step 3.7 Flash ships a 256k-token context window. On pricing, Step 3.7 Flash costs $0.20/1M input tokens versus $1/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

Step 3.7 Flash is ~400% cheaper at $0.20/1M; pay for o4-mini only for coding workflow support.

Decision scorecard

Local evidence first
Signalo4-miniStep 3.7 Flash
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window200k256k
Cheapest output$4/1M tokens$1.15/1M tokens
Provider routes4 tracked3 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose o4-mini when...
  • o4-mini has broader tracked provider coverage for fallback and procurement flexibility.
  • o4-mini uniquely exposes Code execution in local model data.
  • Local decision data tags o4-mini for Coding, RAG, and Agents.
Choose Step 3.7 Flash when...
  • Step 3.7 Flash has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Step 3.7 Flash has the lower cheapest tracked output price at $1.15/1M tokens.
  • Local decision data tags Step 3.7 Flash for Coding, RAG, and Agents.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate Step 3.7 Flash

o4-mini

$1,800

Cheapest tracked route/tier: Replicate API

Step 3.7 Flash

$448

Cheapest tracked route/tier: StepFun

Estimated monthly gap: $1,353. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

o4-mini -> Step 3.7 Flash
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Step 3.7 Flash is $2.85/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Code execution before moving production traffic.
Step 3.7 Flash -> o4-mini
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • o4-mini is $2.85/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • o4-mini adds Code execution in local capability data.

Specs

Specification
Released2025-04-162026-05-29
Context window200k256k
Parameters198B (11B active)
Architecturedecoder onlymixture of experts
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use with conditionsCommercial use with conditions
Knowledge cutoff2025-08-

Pricing and availability

Pricing attributeo4-miniStep 3.7 Flash
Input price$1/1M tokens$0.20/1M tokens
Output price$4/1M tokens$1.15/1M tokens
Providers

Capabilities

Capabilityo4-miniStep 3.7 Flash
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on code execution: o4-mini. Both models share vision, multimodal input, reasoning mode, and function calling, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.

For cost, o4-mini lists $1/1M input and $4/1M output tokens on the cheapest tracked provider, while Step 3.7 Flash lists $0.20/1M input and $1.15/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Step 3.7 Flash lower by about $1.42 per million blended tokens. Availability is 4 providers versus 3, so concentration risk also matters.

Choose o4-mini when coding workflow support and broader provider choice are central to the workload. Choose Step 3.7 Flash when long-context analysis, larger context windows, and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.

FAQ

Which has a larger context window, o4-mini or Step 3.7 Flash?

Step 3.7 Flash supports 256k tokens, while o4-mini supports 200k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, o4-mini or Step 3.7 Flash?

Step 3.7 Flash is cheaper on tracked token pricing. o4-mini costs $1/1M input and $4/1M output tokens. Step 3.7 Flash costs $0.20/1M input and $1.15/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is o4-mini or Step 3.7 Flash open source?

o4-mini is listed under Proprietary. Step 3.7 Flash is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.

Which is better for vision, o4-mini or Step 3.7 Flash?

Both o4-mini and Step 3.7 Flash expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, o4-mini or Step 3.7 Flash?

Both o4-mini and Step 3.7 Flash expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Where can I run o4-mini and Step 3.7 Flash?

o4-mini is available on OpenAI API, OpenRouter, Replicate API, and Vercel AI Gateway. Step 3.7 Flash is available on StepFun, OpenRouter, and NVIDIA NIM. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-29. Data sourced from public model cards and provider documentation.