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 128K-token context window, while DeepSeek V4 Pro ships a 1M-token context window. On MMLU PRO, DeepSeek V4 Pro leads by 4.2 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
DeepSeek V4 Pro fits 8x more tokens; pick it for long-context work and DeepSeek V3.1 for tighter calls.
Decision scorecard
Local evidence first| Signal | DeepSeek V3.1 | DeepSeek V4 Pro |
|---|---|---|
| Best for | provider-routed production | reasoning-heavy apps, tool-calling agents, and long-context analysis |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 128K | 1M |
| Cheapest output | $1/1M tokens | $0.73/1M tokens |
| Provider routes | 10 tracked | 6 tracked |
| Shared benchmarks | 2 shared | MMLU PRO leader |
Decision tradeoffs
- DeepSeek V3.1 has broader tracked provider coverage for fallback and route flexibility.
- DeepSeek V3.1 uniquely exposes Code execution in local model data.
- Local decision data tags DeepSeek V3.1 for Coding, RAG, and Agents.
- 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 $0.73/1M tokens.
- DeepSeek V4 Pro uniquely exposes Reasoning and JSON / 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.
DeepSeek V3.1
$466
Cheapest tracked route/tier: Novita AI
DeepSeek V4 Pro
$472
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $6.31. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Fireworks AI, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
- DeepSeek V4 Pro is $0.27/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Code execution before moving production traffic.
- DeepSeek V4 Pro adds Reasoning and JSON / Tool use in local capability data.
- Provider overlap exists on Fireworks AI, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
- DeepSeek V3.1 is $0.27/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Reasoning and JSON / Tool use before moving production traffic.
- DeepSeek V3.1 adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-08-21 | 2026-04-24 |
| Context window | 128K | 1M |
| Parameters | 671B total, 37B active (MoE) | 1.6T |
| Architecture | Mixture of Experts | Mixture of Experts |
| License | MITOSI-approved | MITOSI-approved |
| Openness | Open source | Open source |
| Weights | Unknown | Available |
| Code | Unknown | Unknown |
| Commercial use | Permitted | Permitted |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | DeepSeek V3.1 | DeepSeek V4 Pro |
|---|---|---|
| Input price | $0.27/1M tokens |
|
| Output price | $1/1M tokens |
|
| Providers |
Capabilities
| Capability | DeepSeek V3.1 | DeepSeek V4 Pro |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | Yes |
| JSON / Tool use | No | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | DeepSeek V3.1 | DeepSeek V4 Pro |
|---|---|---|
| MMLU PRO | 83.3 | 87.5 |
| SWE-bench Verified | 66.0 | 80.6 |
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 reasoning mode: DeepSeek V4 Pro, JSON / Tool use: DeepSeek V4 Pro, JSON / 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 tiered pricing: Off-peak is $0.66/1M input and $1.98/1M output; Peak is $1.32/1M input and $3.96/1M output. A 70/30 input-output blend puts DeepSeek V4 Pro lower by about $0.02 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 10 providers versus 6, 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 128K 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 lists $0.27/1M input and $1/1M output tokens on the cheapest tracked provider. DeepSeek V4 Pro lists tiered pricing: Off-peak is $0.66/1M input and $1.98/1M output; Peak is $1.32/1M input and $3.96/1M output. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. 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 reasoning mode, DeepSeek V3.1 or DeepSeek V4 Pro?
DeepSeek V4 Pro has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for JSON / Tool use, DeepSeek V3.1 or DeepSeek V4 Pro?
DeepSeek V4 Pro has the clearer documented JSON / Tool use signal in this comparison. If JSON / Tool use 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, OpenRouter, NVIDIA NIM, and Together AI. 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
Popular comparisons for DeepSeek V3.1
Popular comparisons for DeepSeek V4 Pro
Last reviewed: 2026-10-17. Data sourced from public model cards and provider documentation.