Home/Compare/Llama 3.1 405B vs DeepSeek V3

Llama 3.1 405B Instruct vs DeepSeek V3

Llama 3.1 405B for Meta ecosystem and broad tooling, DeepSeek V3 for coding benchmarks and cost efficiency.

Pricing source: live OpenRouter model catalog (`/api/v1/models`).

Model A

Llama 3.1 405B Instruct

MetaText
Context Window128K
Knowledge CutoffUnknown
Open model page
Model B

DeepSeek V3

DeepSeekText
Context Window128K
Knowledge CutoffUnknown
Open model page

Editorial Verdict

DeepSeek V3 is the higher-capability model; Llama 3.1 405B is the largest open model.

DeepSeek V3 outperforms Llama 3.1 405B on most benchmarks despite being smaller, demonstrating superior training efficiency. Both are open models available for self-hosting. DeepSeek V3 wins on capability. Llama 3.1 405B wins on being the largest open model for teams that specifically need 405B parameter scale.

Llama 3.1 405B Instruct
  • Largest open-weight model available — 405B parameters
  • Fully open for self-hosting with complete transparency
  • Suitable for enterprise self-hosted deployments requiring maximum model size

Best for: Enterprise deployments specifically requiring 405B parameter scale

DeepSeek V3
  • Higher benchmark performance despite being smaller — better training efficiency
  • Lower compute requirements for inference
  • More recent model with updated training and knowledge

Best for: Teams wanting maximum capability in a self-hosted open model

Pricing sourced from OpenRouter — updates as their catalog changes.

Pricing Comparison

All values pull from OpenRouter and update as their catalog changes.

MetricLlama 3.1 405B InstructDeepSeek V3Winner
Input (per 1M tokens)CustomCustomN/A
Output (per 1M tokens)CustomCustomN/A
Request feeN/AN/AN/A
Image feeN/AN/AN/A

Cost Estimator

Estimate monthly billing using real OpenRouter prices.

Llama 3.1 405B Instruct Total

Variable

DeepSeek V3 Total

Variable
Savings unavailable (pricing not published for one model).

Capability Signals

Scores are directional estimates from model metadata — not official benchmark results.

Llama 3.1 405B InstructMMLU Signal (Reasoning)DeepSeek V3
69%
69%
Llama 3.1 405B InstructHumanEval Signal (Coding)DeepSeek V3
69%
69%
Llama 3.1 405B InstructAgentic Tooling SignalDeepSeek V3
69%
69%
Llama 3.1 405B InstructMultimodal SignalDeepSeek V3
69%
69%

Capabilities Matrix

Feature highlights for architecture and production fit.

Llama 3.1 405B Instruct Strengths

  • Balanced general-purpose profile for chat, extraction, and automation tasks.

DeepSeek V3 Strengths

  • Balanced general-purpose profile for chat, extraction, and automation tasks.

API Implementation

Quick start snippets for each provider style.

Meta (Python)

from openai import OpenAI

client = OpenAI()
response = client.chat.completions.create(
  model="meta/llama-3.1-405b-instruct",
  messages=[{"role": "user", "content": "Hello"}]
)

print(response.choices[0].message.content)

DeepSeek (Python)

from openai import OpenAI

client = OpenAI()
response = client.chat.completions.create(
  model="deepseek/deepseek-v3",
  messages=[{"role": "user", "content": "Hello"}]
)

print(response.choices[0].message.content)

Choose Llama 3.1 405B Instruct when...

  • You want a balanced default for mixed chat and workflow automation workloads.
  • You can measure quality with your own benchmark and prompt set.

Choose DeepSeek V3 when...

  • You want a balanced default for mixed chat and workflow automation workloads.
  • You can measure quality with your own benchmark and prompt set.

Frequently Asked Questions

Practical checks before selecting a production model.

Which model is better for coding?

Coding preference depends on your stack and tool-calling needs. Compare the coding signal row, test with your repository tasks, and validate latency in your target region.

Which model is cheaper at scale?

Input and output token pricing can diverge by workload profile. Use the estimator with your monthly request count and token mix to get a realistic cost difference.

Are these official benchmark numbers?

Pricing is live from OpenRouter. Benchmark rows are ModelsAtlas metadata-based signals and should be treated as directional guidance, not official leaderboard scores.

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