/ Models Index / Llama 3.1 405B

Llama 3.1 405B

Open-Weights · Meta · Meta AI · Released Jul 2024
B-

Good (B-) — Capability Grade

Llama 3.1 405B was Meta's largest open-weights model in the 3.x generation. Strong release-time benchmarks; now legacy. Inference infrastructure cost limits deployment economics.

76
Composite / 100
/ Subscore Breakdown · 6 Capability Dimensions

Where this grade comes from.

General Reasoning
B
Code Generation
B-
Math & STEM
B-
Tool Use & Agency
C
Multimodal
D
Safety & Alignment
B-
/ Key Events & Disclosures

Release timeline & positioning.

  • Released Jul 2024
  • Largest Llama 3.x variant
  • Now legacy generation
  • Superseded by Llama 4 Behemoth

/ Best for

Legacy production deployments only. New deployments should use Llama 4 Behemoth or alternative.

/ Watch out for

Superseded. Inference cost is non-trivial for 405B parameter inference.