{"schema":"postcutoff/event@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/e/2024-07-23-llama-3-1-405b/","md":"https://postcutoff.com/e/2024-07-23-llama-3-1-405b/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2024-07-23-llama-3-1-405b","date":"2024-07-23","date_precision":"day","short_title":"Llama 3.1 405B: the first frontier-class open-weights model","deck":null,"takeaway":"Meta released Llama 3.1 including a 405B-parameter model with 128K context, which Meta said was competitive with GPT-4o and Claude 3.5 Sonnet — the first openly downloadable model at the frontier.","category":"open-source","category_label":"Open source","importance":4,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":[{"n":1,"title":"Introducing Llama 3.1 (Meta AI)","url":"https://ai.meta.com/blog/meta-llama-3-1/","type":"official","group":"primary","domain":"ai.meta.com"},{"n":2,"title":"The Llama 3 Herd of Models (arXiv)","url":"https://arxiv.org/abs/2407.21783","type":"paper","group":"primary","domain":"arxiv.org"}],"official":2,"filed":"2026-09-29","updated":"2026-09-29","orgs":["Meta"],"title":"Llama 3.1 405B: the first frontier-class open-weights model","summary":"Meta released Llama 3.1 including a 405B-parameter model with 128K context, which Meta said was competitive with GPT-4o and Claude 3.5 Sonnet — the first openly downloadable model at the frontier.","key_facts":["Released 23 July 2024","Sizes: 8B, 70B, 405B; 128K context","405B trained on over 15T tokens using more than 16,000 H100 GPUs","Mark Zuckerberg published 'Open Source AI Is the Path Forward' alongside"],"key_numbers":[],"tags":["llm","open-weights","meta","frontier"],"science":null,"body_md":"## What happened\n\nMeta released open weights for a dense 405B model along with a detailed technical report.\n\n## Why it matters\n\nNarrowed the open–closed gap to months; open frontier weights reshaped policy debates and enabled wide distillation.","disputed":[],"related":[{"id":"2025-04-05-llama-4","url":"https://postcutoff.com/e/2025-04-05-llama-4/","date":"2025-04-05","date_precision":"day","short_title":"Meta releases Llama 4 Scout and Maverick","deck":null,"takeaway":"Signaled Meta's loss of open-weights leadership to Chinese labs (DeepSeek, Qwen, Kimi) and precipitated its superintelligence reorganization.","category":"open-source","category_label":"Open source","importance":3,"confidence":"medium","status":{"key":"partly","labels":["Partly confirmed"]},"sources":2,"official":1,"filed":"2026-09-29","updated":"2026-09-29","orgs":["Meta"]},{"id":"2024-04-18-llama-3","url":"https://postcutoff.com/e/2024-04-18-llama-3/","date":"2024-04-18","date_precision":"day","short_title":"Meta releases Llama 3 (8B, 70B)","deck":null,"takeaway":"Showed the benefit of training small models far past Chinchilla-optimal, and narrowed the open/closed gap.","category":"open-source","category_label":"Open source","importance":3,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":2,"official":2,"filed":"2026-09-29","updated":"2026-09-29","orgs":["Meta"]}],"people":[{"id":"mark-zuckerberg","name":"Mark Zuckerberg","url":"https://postcutoff.com/person/mark-zuckerberg/"}],"posts":[],"videos":[],"models":[],"changes":[{"date":"2026-09-29","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-09-29","run":null,"sources_read":null,"updated":"2026-09-29","human_review":null,"version":{"date":"2026-10-04"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":null,"in_training_data":true},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":null,"in_training_data":true},{"model_id":"gemini-4-hydrogen","name":"Gemini 4 Hydrogen","cutoff":"2026-03","days_after":null,"in_training_data":true},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":null,"in_training_data":true}],"short_url":"https://postcutoff.com/s/llama-3-1-405b-first"}