LLM Reference

DeepSeek V3 vs Step 3.7 Flash

DeepSeek V3 (2024) and Step 3.7 Flash (2026) are frontier reasoning models from DeepSeek and StepFun. DeepSeek V3 ships a 64k-token context window, while Step 3.7 Flash ships a 256k-token context window. On pricing, DeepSeek V3 costs $0.10/1M input tokens versus $0.20/1M 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.

DeepSeek V3 is ~100% cheaper at $0.10/1M; pay for Step 3.7 Flash only for reasoning depth.

Decision scorecard

Local evidence first
SignalDeepSeek V3Step 3.7 Flash
Best fortool-calling agents and provider-routed productionreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, Agents, and ClassificationCoding, RAG, and Agents
Context window64k256k
Cheapest output$0.30/1M tokens$1.15/1M tokens
Provider routes13 tracked3 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose DeepSeek V3 when...
  • DeepSeek V3 has the lower cheapest tracked output price at $0.30/1M tokens.
  • DeepSeek V3 has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags DeepSeek V3 for Coding, Agents, and Classification.
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 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • 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 DeepSeek V3

DeepSeek V3

$155

Cheapest tracked route/tier: Bitdeer AI

Step 3.7 Flash

$448

Cheapest tracked route/tier: StepFun

Estimated monthly gap: $293. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

DeepSeek V3 -> Step 3.7 Flash
  • Provider overlap exists on OpenRouter and NVIDIA NIM; start route-level A/B tests there.
  • Step 3.7 Flash is $0.85/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Step 3.7 Flash adds Vision, Multimodal, and Reasoning in local capability data.
Step 3.7 Flash -> DeepSeek V3
  • Provider overlap exists on OpenRouter and NVIDIA NIM; start route-level A/B tests there.
  • DeepSeek V3 is $0.85/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.

Specs

Specification
Released2024-12-262026-05-29
Context window64k256k
Parameters671B198B (11B active)
ArchitectureMixture of ExpertsMixture of Experts
LicenseMITOSI-approvedProprietary
OpennessOpen sourceProprietary
WeightsAvailableNot released
CodeUnknownUnknown
Commercial useCommercial use: permittedCommercial use: conditional
Knowledge cutoff2024-04-

Pricing and availability

Pricing attributeDeepSeek V3Step 3.7 Flash
Input price$0.10/1M tokens$0.20/1M tokens
Output price$0.30/1M tokens$1.15/1M tokens
Providers

Capabilities

CapabilityDeepSeek V3Step 3.7 Flash
VisionNoYes
MultimodalNoYes
ReasoningNoYes
JSON / Tool useYesYes
Structured outputsYesYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark scores are currently available for this pair.

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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.