{
  "id": "gpt-j-6b",
  "name": "GPT-J 6B",
  "identifiers": {
    "huggingface": [
      "EleutherAI/gpt-j-6b",
      "EleutherAI/gpt-j-6B"
    ]
  },
  "developer": "EleutherAI (Ben Wang, Aran Komatsuzaki)",
  "release_date": {
    "value": "2021-06",
    "source": "https://github.com/kingoflolz/mesh-transformer-jax/commit/b0c18e5205ea5ff7f97a7047e964fc04a78ea42b",
    "status": "partial",
    "note": "Repo commit 'gpt-j-6b release' is 2021-06-09 UTC; the linked announcement post's URL is dated 2021-06-04. Month is certain, day is not."
  },
  "weights_status": "open",
  "availability": {
    "value": "available",
    "checked": "2026-09-24",
    "source": "https://huggingface.co/EleutherAI/gpt-j-6b"
  },
  "license": {
    "value": "Apache 2.0",
    "source": "https://github.com/kingoflolz/mesh-transformer-jax",
    "status": "recorded",
    "note": "Repo README: 'The weights of GPT-J-6B are licensed under version 2.0 of the Apache License.'"
  },
  "architecture": {
    "family": "decoder_only",
    "note": "Card: 28 layers, d_model 4096, d_ff 16384, 16 heads of 256 dims; RoPE applied to 64 dimensions of each head. Trained with Mesh Transformer JAX.",
    "n_layers": {
      "value": 28,
      "source": "https://huggingface.co/EleutherAI/gpt-j-6b/raw/47e169305d2e8376be1d31e765533382721b2cc1/config.json",
      "status": "recorded"
    },
    "hidden_size": {
      "value": 4096,
      "source": "https://huggingface.co/EleutherAI/gpt-j-6b/raw/47e169305d2e8376be1d31e765533382721b2cc1/config.json",
      "status": "recorded"
    },
    "n_heads": {
      "value": 16,
      "source": "https://huggingface.co/EleutherAI/gpt-j-6b/raw/47e169305d2e8376be1d31e765533382721b2cc1/config.json",
      "status": "recorded"
    },
    "vocab_size": {
      "value": 50400,
      "source": "https://huggingface.co/EleutherAI/gpt-j-6b/raw/47e169305d2e8376be1d31e765533382721b2cc1/config.json",
      "status": "recorded",
      "note": "Card: embedding matrix is 50400 but only 50257 entries are used by the GPT-2 tokenizer."
    },
    "positional_encoding": {
      "value": "rotary (RoPE), partial: 64 of 256 dims per head",
      "source": "https://huggingface.co/EleutherAI/gpt-j-6b/blob/47e169305d2e8376be1d31e765533382721b2cc1/README.md",
      "status": "recorded"
    },
    "context_length": {
      "value": 2048,
      "source": "https://huggingface.co/EleutherAI/gpt-j-6b/raw/47e169305d2e8376be1d31e765533382721b2cc1/config.json",
      "status": "recorded"
    }
  },
  "training_data": {
    "value": "The Pile (EleutherAI's ~800GB curated English corpus); 402B tokens over 383,500 steps.",
    "source": "https://huggingface.co/EleutherAI/gpt-j-6b/blob/47e169305d2e8376be1d31e765533382721b2cc1/README.md",
    "status": "recorded"
  },
  "techniques": [
    "transformer-decoder",
    "rotary-position-embedding",
    "byte-pair-encoding"
  ],
  "primary_sources": [
    "https://huggingface.co/EleutherAI/gpt-j-6b/blob/47e169305d2e8376be1d31e765533382721b2cc1/README.md",
    "https://github.com/kingoflolz/mesh-transformer-jax",
    "https://github.com/kingoflolz/mesh-transformer-jax/commit/b0c18e5205ea5ff7f97a7047e964fc04a78ea42b",
    "https://huggingface.co/EleutherAI/gpt-j-6b/raw/47e169305d2e8376be1d31e765533382721b2cc1/config.json"
  ],
  "record_history": [
    {
      "date": "2026-09-24",
      "change": "created from primary sources (Phase 1 seed, batch 2)",
      "by": "wilson-pruitt + claude"
    },
    {
      "date": "2026-09-24",
      "change": "availability checked and recorded",
      "by": "wilson-pruitt + claude"
    }
  ]
}