DeepSeek V4 Pro vs Llama 3.1 405B Instruct
DeepSeek V4 Pro (2026) and Llama 3.1 405B Instruct (2024) are frontier reasoning models from DeepSeek and AI at Meta. DeepSeek V4 Pro ships a 1m-token context window, while Llama 3.1 405B Instruct ships a 128k-token context window. On Massive Multitask Language Understanding, DeepSeek V4 Pro leads by 1.5 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 is ~452% cheaper at $0.43/1M; pay for Llama 3.1 405B Instruct only for provider fit.
Decision scorecard
Local evidence first| Signal | DeepSeek V4 Pro | Llama 3.1 405B Instruct |
|---|---|---|
| Best for | reasoning-heavy apps, tool-calling agents, and long-context analysis | provider-routed production |
| Decision fit | Coding, RAG, and Agents | RAG, Long context, and Classification |
| Context window | 1m | 128k |
| Cheapest output | $0.87/1M tokens | $2.40/1M tokens |
| Provider routes | 5 tracked | 11 tracked |
| Shared benchmarks | Massive Multitask Language Understanding leader | 1 shared |
Decision tradeoffs
- DeepSeek V4 Pro holds a shared-benchmark lead on Massive Multitask Language Understanding, ahead by 1.5 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 and JSON / Tool use in local model data.
- Local decision data tags DeepSeek V4 Pro for Coding, RAG, and Agents.
- Llama 3.1 405B Instruct has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Llama 3.1 405B Instruct for RAG, Long context, and Classification.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
DeepSeek V4 Pro
$566
Cheapest tracked route/tier: DeepSeek Platform
Llama 3.1 405B Instruct
$2,520
Cheapest tracked route/tier: AWS Bedrock
Estimated monthly gap: $1,955. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Fireworks AI; start route-level A/B tests there.
- Llama 3.1 405B Instruct is $1.53/1M 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.
- Provider overlap exists on Fireworks AI; start route-level A/B tests there.
- DeepSeek V4 Pro is $1.53/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- DeepSeek V4 Pro adds Reasoning and JSON / Tool use in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-24 | 2024-07-23 |
| Context window | 1m | 128k |
| Parameters | 1.6T | 405B |
| Architecture | Mixture of Experts | Decoder Only |
| License | MITOSI-approved | Llama 3 Community |
| Openness | Open source | Open weights |
| Weights | Available | Available |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: permitted | Commercial use: conditional |
| Knowledge cutoff | - | 2023-12 |
Pricing and availability
| Pricing attribute | DeepSeek V4 Pro | Llama 3.1 405B Instruct |
|---|---|---|
| Input price | $0.43/1M tokens | $2.40/1M tokens |
| Output price | $0.87/1M tokens | $2.40/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek V4 Pro | Llama 3.1 405B Instruct |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | Yes | No |
| JSON / Tool use | Yes | No |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | DeepSeek V4 Pro | Llama 3.1 405B Instruct |
|---|---|---|
| Massive Multitask Language Understanding | 90.1 | 88.6 |
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Last reviewed: 2026-07-11. Data sourced from public model cards and provider documentation.