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Llama 4 405B

Meta's flagship open-weight model, sparse MoE design competitive with closed-frontier flagships.

Updated

Quick facts

Released
Apr 2025
Context
256K tokens
Output / 1M
Pricing not published
License
Llama 4 Community License

About Llama 4 405B

Llama 4 introduced Meta's first sparse mixture-of-experts architecture and the 405B variant is the open-weight model most often compared head-to-head with GPT-5 and Claude Opus on benchmarks. It's freely downloadable under the Llama Community License with revenue-cap caveats.

Serving 405B requires significant infrastructure, most users access it via Together, Fireworks, Groq, or OpenRouter rather than self-hosting.

Benchmarks

Published scores from Meta's model card or independent leaderboards. We do not publish numbers we cannot source, see methodology.

HumanEval
,
Python coding pass@1
MMLU
,
Broad academic knowledge
GPQA
,
Graduate-level reasoning
SWE-bench
,
Real software-engineering tasks
Benchmark scores not yet available. We only publish numbers we can source from official model cards or independent leaderboards, see methodology.

Capabilities

Strengths

  • Strongest open-weight model at launch
  • Multimodal (text + vision)
  • Wide hosting availability

Tracked weaknesses

  • Custom license with revenue caps
  • Heavy to self-host

Pricing

Per-million-token rates as published by Meta.

Per-token pricing not yet published for Llama 4 405B. Check the official provider site for current tiers.

Call Llama 4 405B from your code

Drop-in snippet for the Meta SDK. Set your API key in the environment and run.

typescript
import OpenAI from "openai";

const client = new OpenAI({
  // Use OPENAI_API_KEY for OpenAI, or your provider's key + baseURL.
  apiKey: process.env.OPENAI_API_KEY,
});

const completion = await client.chat.completions.create({
  model: "llama-4-405b",
  messages: [
    { role: "user", content: "What's the time complexity of quicksort?" },
  ],
});

console.log(completion.choices[0].message.content);

Best for

Tasks where Llama 4 405B ranks among LLMDex's top picks.

Compare Llama 4 405B with…

Frequently asked

  • How much does Llama 4 405B cost?
    Meta has not published per-token API pricing for Llama 4 405B at the time of writing. Check the official site for current pricing tiers, or compare against alternative models on LLMDex.
  • What is Llama 4 405B's context window?
    Llama 4 405B supports a context window of 256K tokens.
  • Is Llama 4 405B open source?
    Llama 4 405B ships with open weights under the Llama 4 Community License license. You can self-host it, fine-tune it, and (subject to the license terms) deploy it commercially.
  • When was Llama 4 405B released?
    Llama 4 405B was released on Apr 5, 2025 by Meta.
  • What is Llama 4 405B's knowledge cutoff?
    Llama 4 405B's training data has a knowledge cutoff of Dec 2024. For information after that date you'll need a tool-use or web-search wrapper.
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