LLM Reference

DeepSeek V3.1 vs DeepSeek V4 Pro

DeepSeek V3.1 (2025) and DeepSeek V4 Pro (2026) are frontier reasoning models from DeepSeek. DeepSeek V3.1 ships a 64k-token context window, while DeepSeek V4 Pro ships a 1m-token context window. On MMLU PRO, DeepSeek V4 Pro leads by 4.2 pts. On pricing, DeepSeek V3.1 costs $0.27/1M input tokens versus $0.43/1M 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 V3.1 is ~61% cheaper at $0.27/1M; pay for DeepSeek V4 Pro only for reasoning depth.

Decision scorecard

Local evidence first
SignalDeepSeek V3.1DeepSeek V4 Pro
Best formultimodal apps and provider-routed productionreasoning-heavy apps, tool-calling agents, and long-context analysis
Decision fitCoding, Agents, and VisionCoding, RAG, and Agents
Context window64k1m
Cheapest output$1/1M tokens$0.87/1M tokens
Provider routes8 tracked5 tracked
Shared benchmarks2 rowsMMLU PRO leader

Decision tradeoffs

Choose DeepSeek V3.1 when...
  • DeepSeek V3.1 has broader tracked provider coverage for fallback and procurement flexibility.
  • DeepSeek V3.1 uniquely exposes Vision, Multimodal, and Code execution in local model data.
  • Local decision data tags DeepSeek V3.1 for Coding, Agents, and Vision.
Choose DeepSeek V4 Pro when...
  • DeepSeek V4 Pro holds a shared-benchmark lead on MMLU PRO, ahead by 4.2 points.
  • DeepSeek V4 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • DeepSeek V4 Pro has the lower cheapest tracked output price at $0.87/1M tokens.
  • DeepSeek V4 Pro uniquely exposes Reasoning, Function calling, and Tool use in local model data.
  • Local decision data tags DeepSeek V4 Pro 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 V3.1

DeepSeek V3.1

$466

Cheapest tracked route/tier: Novita AI

DeepSeek V4 Pro

$566

Cheapest tracked route/tier: DeepSeek Platform

Estimated monthly gap: $99.50. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

DeepSeek V3.1 -> DeepSeek V4 Pro
  • Provider overlap exists on Fireworks AI, Vercel AI Gateway, and Novita AI; start route-level A/B tests there.
  • DeepSeek V4 Pro is $0.13/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Code execution before moving production traffic.
  • DeepSeek V4 Pro adds Reasoning, Function calling, and Tool use in local capability data.
DeepSeek V4 Pro -> DeepSeek V3.1
  • Provider overlap exists on Fireworks AI, Vercel AI Gateway, and Novita AI; start route-level A/B tests there.
  • DeepSeek V3.1 is $0.13/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Check replacement coverage for Reasoning, Function calling, and Tool use before moving production traffic.
  • DeepSeek V3.1 adds Vision, Multimodal, and Code execution in local capability data.

Specs

Specification
Released2025-08-212026-04-24
Context window64k1m
Parameters671B total, 37B active (MoE)1.6T
Architecturemixture of expertsMixture of Experts (MoE) with CSA+HCA hybrid attention
LicenseMIT(OSI)MIT(OSI)
OpennessOpen sourceOpen source
Commercial useCommercial use allowedCommercial use allowed
Knowledge cutoff--

Pricing and availability

Pricing attributeDeepSeek V3.1DeepSeek V4 Pro
Input price$0.27/1M tokens$0.43/1M tokens
Output price$1/1M tokens$0.87/1M tokens
Providers

Capabilities

CapabilityDeepSeek V3.1DeepSeek V4 Pro
VisionYesNo
MultimodalYesNo
ReasoningNoYes
Function callingNoYes
Tool useNoYes
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkDeepSeek V3.1DeepSeek V4 Pro
MMLU PRO83.387.5
SWE-bench Verified66.080.6

Deep dive

On shared benchmark coverage, MMLU PRO has DeepSeek V3.1 at 83.3 and DeepSeek V4 Pro at 87.5, with DeepSeek V4 Pro ahead by 4.2 points; SWE-bench Verified has DeepSeek V3.1 at 66 and DeepSeek V4 Pro at 80.6, with DeepSeek V4 Pro ahead by 14.6 points. The largest visible gap is 14.6 points on SWE-bench Verified, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.

The capability footprint differs most on vision: DeepSeek V3.1, multimodal input: DeepSeek V3.1, reasoning mode: DeepSeek V4 Pro, function calling: DeepSeek V4 Pro, tool use: DeepSeek V4 Pro, and code execution: DeepSeek V3.1. Both models share structured outputs, 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, DeepSeek V3.1 lists $0.27/1M input and $1/1M output tokens on the cheapest tracked provider, while DeepSeek V4 Pro lists $0.43/1M input and $0.87/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts DeepSeek V3.1 lower by about $0.08 per million blended tokens. Availability is 8 providers versus 5, so concentration risk also matters.

Choose DeepSeek V3.1 when coding workflow support, lower input-token cost, and broader provider choice are central to the workload. Choose DeepSeek V4 Pro when reasoning depth and larger context windows are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Which has a larger context window, DeepSeek V3.1 or DeepSeek V4 Pro?

DeepSeek V4 Pro supports 1m tokens, while DeepSeek V3.1 supports 64k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, DeepSeek V3.1 or DeepSeek V4 Pro?

DeepSeek V3.1 is cheaper on tracked token pricing. DeepSeek V3.1 costs $0.27/1M input and $1/1M output tokens. DeepSeek V4 Pro costs $0.43/1M input and $0.87/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is DeepSeek V3.1 or DeepSeek V4 Pro open source?

DeepSeek V3.1 is listed under MIT. DeepSeek V4 Pro is listed under MIT. 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, DeepSeek V3.1 or DeepSeek V4 Pro?

DeepSeek V3.1 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, DeepSeek V3.1 or DeepSeek V4 Pro?

DeepSeek V3.1 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run DeepSeek V3.1 and DeepSeek V4 Pro?

DeepSeek V3.1 is available on Microsoft Foundry, Fireworks AI, NVIDIA NIM, Together AI, and AWS Bedrock. DeepSeek V4 Pro is available on DeepSeek Platform, Fireworks AI, OpenRouter, Vercel AI Gateway, and Novita AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-31. Data sourced from public model cards and provider documentation.