{
  "title": "LLM Model Sizes Over Time",
  "description": "Parameter counts for major language models from 2019 to 2026. Log scale. Dashed circles = estimated, double rings = not yet released.",
  "date_range": "2019-02-14 to 2026-05-01",
  "record_count": 38,
  "last_updated": "2026-04-16",
  "sources": [
    { "name": "Anthropic model announcements", "url": "https://www.anthropic.com/news" },
    { "name": "OpenAI model announcements", "url": "https://openai.com/index" },
    { "name": "Artificial Analysis", "url": "https://artificialanalysis.ai" },
    { "name": "Epoch AI", "url": "https://epochai.org" },
    { "name": "Axios: Anthropic releases Opus 4.7", "url": "https://www.axios.com/2026/04/16/anthropic-claude-opus-model-mythos" },
    { "name": "Fortune: Anthropic Mythos", "url": "https://fortune.com/2026/03/26/anthropic-says-testing-mythos-powerful-new-ai-model" }
  ],
  "caveat": "No frontier lab has disclosed official parameter counts since GPT-3. All values for 2023+ models are community estimates from leaks, benchmark analysis, and scaling projections.",
  "fields": {
    "name": "Model name",
    "date": "Public release date (ISO 8601)",
    "params_billions": "Estimated parameter count in billions",
    "org": "Developing organization",
    "estimated": "Whether parameter count is estimated (vs. officially disclosed)",
    "unreleased": "Whether model is not yet publicly available",
    "note": "Additional context"
  }
}