DeepSeek V4 Pro vs Llama 3.1 405B

Name: DeepSeek V4 Pro
Author: DeepSeek

DeepSeek V4 Pro (2026) and Llama 3.1 405B (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 ships a 128k-token context window. On Google-Proof Q&A, DeepSeek V4 Pro leads by 38.6 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 Llama 3.1 405B for tighter calls.

Decision scorecard

Local evidence first

Signal	DeepSeek V4 Pro	Llama 3.1 405B	How to read it
Best for	reasoning-heavy apps, tool-calling agents, and long-context analysis	general production evaluation	Use-case synthesis from product type, capability flags, context, and provider data.
Decision fit	Coding, RAG, and Agents	Coding, Long context, and Classification	Primary workload tags from local decision data.
Context window	1m	128k	Higher is better when prompts, retrieval chunks, or transcripts are large.
Cheapest output	$0.87/1M tokens	-	Cheapest tracked provider route; verify your exact region and tier.
Provider routes	5 tracked	0 tracked	Broader coverage can reduce vendor lock-in and fallback risk.
Shared benchmarks	Google-Proof Q&A leader	4 shared	Visible benchmark lead is 38.6 points on Google-Proof Q&A.

Decision tradeoffs

Choose DeepSeek V4 Pro when...

DeepSeek V4 Pro holds a shared-benchmark lead on Google-Proof Q&A, ahead by 38.6 points.
DeepSeek V4 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
DeepSeek V4 Pro has broader tracked provider coverage for fallback and route flexibility.
DeepSeek V4 Pro uniquely exposes Reasoning, JSON / Tool use, and Structured outputs in local model data.
Local decision data tags DeepSeek V4 Pro for Coding, RAG, and Agents.

Choose Llama 3.1 405B when...

Llama 3.1 405B holds a shared-benchmark lead on HumanEval, ahead by 12.2 points.
Local decision data tags Llama 3.1 405B for Coding, Long context, and Classification.

Monthly cost at traffic

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

Requests / monthInput tokens / requestOutput tokens / request

DeepSeek V4 Pro

$566

Cheapest tracked route/tier: DeepSeek Platform

Llama 3.1 405B

Unavailable

No complete token price in local provider data

Cost delta unavailable until both models have sourced input and output token prices.

Switch friction

DeepSeek V4 Pro -> Llama 3.1 405B

No overlapping tracked provider route is sourced for DeepSeek V4 Pro and Llama 3.1 405B; plan for SDK, billing, or endpoint changes.
Check replacement coverage for Reasoning, JSON / Tool use, and Structured outputs before moving production traffic.

Llama 3.1 405B -> DeepSeek V4 Pro

No overlapping tracked provider route is sourced for Llama 3.1 405B and DeepSeek V4 Pro; plan for SDK, billing, or endpoint changes.
DeepSeek V4 Pro adds Reasoning, JSON / Tool use, and Structured outputs in local capability data.

Specs

Specification	DeepSeek V4 Pro DeepSeek	Llama 3.1 405B AI at Meta
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
Input price	$0.43/1M tokens	-
Output price	$0.87/1M tokens	-
Providers	DeepSeek Platform Fireworks AI OpenRouter Vercel AI Gateway Novita AI	-

Capabilities

Capability	DeepSeek V4 Pro	Llama 3.1 405B
Vision	No	No
Multimodal	No	No
Reasoning	Yes	No
JSON / Tool use	Yes	No
Structured outputs	Yes	No
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
Google-Proof Q&A	90.1	51.5
HumanEval	76.8	89.0
Chatbot Arena	1456.0	1228.0
Massive Multitask Language Understanding	90.1	88.6

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Last reviewed: 2026-07-09. Data sourced from public model cards and provider documentation.

Both models

DeepSeek V4 Pro Llama 3.1 405B