Llama 3.1 405B vs GPT-4o Mini: Detailed Comparison

Choosing between Llama 3.1 405B (Meta) and GPT-4o Mini (OpenAI) comes down to three things: per-token pricing, context window, and which capability matters most for your workload. Llama 3.1 405B costs $3.50/M input vs $0.15/M for GPT-4o Mini; context windows are 128K vs 128K tokens. Detailed breakdown below.

Side-by-side specs

SpecLlama 3.1 405BGPT-4o Mini
ProviderMetaOpenAI
Released2024-07-232024-07-18
Input price $3.50/M $0.15/M
Output price $3.50/M $0.60/M
Cached input $0.0750/M
Context window 128K 128K
Max output 4K 16K
Modalities text text image
Tokenizer llama-3 o200k_base

Capability matrix

CapabilityLlama 3.1 405BGPT-4o Mini
function calling Yes Yes
json mode Yes Yes
streaming Yes Yes
vision No Yes

Per-call cost on typical workloads

Workload (in/out tokens)Llama 3.1 405BGPT-4o MiniCheaper by
Standard chat (1K / 500) $0.005250 $0.000450 GPT-4o Mini by $0.004800
RAG (4K / 500) $0.015750 $0.000900 GPT-4o Mini by $0.014850
Long doc (20K / 1K) $0.073500 $0.003600 GPT-4o Mini by $0.069900
Very long context (100K / 2K) $0.355250 $0.015900 GPT-4o Mini by $0.339350

When to choose Llama 3.1 405B over GPT-4o Mini

  • Llama 3.1 405B fits when your stack is already on Meta (single billing, SDK, observability surface).

When to choose GPT-4o Mini over Llama 3.1 405B

  • Per-token input cost is 96% lower than Llama 3.1 405B.
  • Supports vision — Llama 3.1 405B does not.

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