How the major AI models are actually related

Every edge in the Claude tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• Claude 2 (Jul 11, 2023) — succession of Claude 1
• Claude Instant 1.2 (Aug 9, 2023) — distilled from of Claude 1 — Anthropic positioned Claude Instant as a smaller, faster sibling of the Claude flagship; sourced to the Claude 2 announcement.
• Claude 2.1 (Nov 21, 2023) — post-training of Claude 2 — Anthropic documented Claude 2.1 as an iterative update on Claude 2 with the 200K context extension, not a new base.
• Claude 3 Opus (Mar 4, 2024) — new base of Claude 2.1 — Anthropic introduced the Claude 3 family as a new generation of base models, not a Claude 2 fine-tune.
• Claude 3 Sonnet (Mar 4, 2024) — succession of Claude 3 Opus — Anthropic shipped Opus / Sonnet / Haiku as the three tiers of the Claude 3 generation simultaneously.
• Claude 3 Haiku (Mar 13, 2024) — succession of Claude 3 Opus
• Claude 3.5 Sonnet (Jun 20, 2024) — succession of Claude 3 Sonnet
• 3.5 Sonnet (new) (Oct 22, 2024) — post-training of Claude 3.5 Sonnet — Anthropic documented the October 2024 'new 3.5 Sonnet' as an upgraded version under the same model id.
• Claude 3.5 Haiku (Nov 4, 2024) — distilled from of 3.5 Sonnet (new) — Anthropic documented Claude 3.5 Haiku as a smaller sibling sharing the 3.5 generation training.
• Claude 3.7 Sonnet (Feb 24, 2025) — succession of 3.5 Sonnet (new)
• Claude Sonnet 4 (May 22, 2025) — new base of Claude 3.7 Sonnet — Anthropic introduced Claude 4 as a new generation, with Opus 4 and Sonnet 4 as new bases rather than fine-tunes of 3.7.
• Claude Opus 4 (May 22, 2025) — new base of Claude 3.7 Sonnet
• Claude Opus 4.7 (Apr 16, 2026) — succession of Claude Opus 4
• Claude Opus 4.7 (Apr 16, 2026) — succession of Claude Sonnet 4

Every edge in the ChatGPT tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• GPT-3.5 (Nov 30, 2022) — post-training of GPT-3 — OpenAI's GPT-3.5 (text-davinci series and ChatGPT launch) was an RLHF-fine-tuned descendant of the GPT-3 base, per OpenAI's InstructGPT paper and the ChatGPT launch post.
• GPT-4 (Mar 14, 2023) — new base of GPT-3.5 — OpenAI introduced GPT-4 as a new base model, not a GPT-3.5 fine-tune.
• GPT-4 Turbo (Nov 6, 2023) — post-training of GPT-4 — OpenAI documented GPT-4 Turbo at DevDay 2023 as the same generation with extended context and updated training data.
• GPT-4o (May 13, 2024) — new base of GPT-4 Turbo — OpenAI introduced GPT-4o as a new natively-multimodal base model.
• GPT-4o mini (Jul 18, 2024) — distilled from of GPT-4o — OpenAI positioned GPT-4o mini as the smaller, distilled sibling of GPT-4o.
• o1-preview (Sep 12, 2024) — new base of GPT-4o — OpenAI introduced the o-series as a separate reasoning track; o1 was trained to use long chain-of-thought at inference time.
• o1 (Dec 5, 2024) — succession of o1-preview
• o3-mini (Jan 31, 2025) — succession of o1
• GPT-4.1 (Apr 14, 2025) — succession of GPT-4o
• o4-mini (Apr 16, 2025) — distilled from of o3 — OpenAI positioned o4-mini as the smaller sibling shipped alongside o3.
• o3 (Apr 16, 2025) — succession of o3-mini
• GPT-5 (Aug 7, 2025) — lines merged of GPT-4.1 — OpenAI introduced GPT-5 as a unified router that combines the GPT chat line and the o-series reasoning track into one model id.
• GPT-5 (Aug 7, 2025) — lines merged of o3
• GPT-5.5 (Apr 23, 2026) — succession of GPT-5

Every edge in the Gemini tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• PaLM 2 (May 10, 2023) — new base of Bard (LaMDA) — Google introduced PaLM 2 as a new base model powering an upgraded Bard.
• Gemini 1.0 Pro (Dec 6, 2023) — new base of PaLM 2 — Google's Gemini 1.0 was a new natively-multimodal architecture, not a PaLM 2 fine-tune.
• Gemini 1.0 Ultra (Feb 8, 2024) — succession of Gemini 1.0 Pro
• Gemini 1.5 Pro (Feb 15, 2024) — new base of Gemini 1.0 Ultra — Google introduced Gemini 1.5 with a new mixture-of-experts architecture and the 1M context, not a 1.0 fine-tune.
• Gemini 1.5 Flash (May 14, 2024) — distilled from of Gemini 1.5 Pro — Google described Gemini 1.5 Flash as a distilled smaller sibling of 1.5 Pro.
• Gemini 2.0 Flash (Dec 11, 2024) — succession of Gemini 1.5 Flash
• Gemini 2.0 Pro Exp (Feb 5, 2025) — succession of Gemini 1.5 Pro
• Gemini 2.5 Pro (Mar 25, 2025) — succession of Gemini 2.0 Pro Exp
• Gemini 2.5 Flash (Jun 17, 2025) — succession of Gemini 2.0 Flash
• 2.5 Flash-Lite (Jul 22, 2025) — distilled from of Gemini 2.5 Flash — Google positioned Flash-Lite as the smallest sibling of the 2.5 Flash family.
• Gemini 3 Pro (Nov 18, 2025) — new base of Gemini 2.5 Pro — Google introduced Gemini 3 as a new generation flagship.
• Gemini 3 Flash (Dec 17, 2025) — succession of Gemini 2.5 Flash
• Gemini 3.1 Pro (Feb 19, 2026) — succession of Gemini 3 Pro
• 3.1 Flash-Lite (Mar 3, 2026) — distilled from of Gemini 3 Flash

Every edge in the Grok tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• Grok 1.5 (Mar 28, 2024) — post-training of Grok 1 — xAI documented Grok 1.5 as a successor that extended Grok 1's context and reasoning, broadly within the same generation.
• Grok 2 (Aug 13, 2024) — new base of Grok 1.5 — xAI introduced Grok 2 as a new base.
• Grok 3 (Feb 17, 2025) — new base of Grok 2 — xAI introduced Grok 3 trained on the Memphis Colossus cluster as a new base.
• Grok 4 (Jul 9, 2025) — new base of Grok 3
• Grok 4.1 (Nov 17, 2025) — post-training of Grok 4
• Grok 4.1 Fast (Nov 19, 2025) — distilled from of Grok 4.1 — xAI positioned Grok 4.1 Fast as a smaller, faster sibling shipped two days after 4.1.
• Grok 4.20 (Mar 10, 2026) — succession of Grok 4.1

Every edge in the Llama tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• Llama 2 (Jul 18, 2023) — new base of LLaMA 1 — Meta's Llama 2 paper documents it as a new pretraining run with substantially larger data and the open license shift.
• Code Llama (Aug 24, 2023) — fine-tune of Llama 2 — Meta's Code Llama paper documents it as a fine-tune of Llama 2 on code data.
• Llama 3 (Apr 18, 2024) — new base of Llama 2 — Meta's Llama 3 release notes document it as a new pretraining run with updated tokenizer.
• Llama 3.1 (Jul 23, 2024) — post-training of Llama 3 — Meta's Llama 3.1 release added the 405B size and the long-context post-training; documented as same generation.
• Llama 3.2 (Sep 25, 2024) — post-training of Llama 3.1 — Meta's Llama 3.2 release added vision and edge-sized variants.
• Llama 3.3 70B (Dec 6, 2024) — post-training of Llama 3.2
• Llama 4 Scout (Apr 5, 2025) — new base of Llama 3.3 70B — Meta's Llama 4 release introduced a new mixture-of-experts architecture as a new base.
• Llama 4 Maverick (Apr 5, 2025) — new base of Llama 3.3 70B
• Muse Spark (Apr 8, 2026) — new base of Llama 4 Maverick — Meta described Muse Spark as the closed-weights successor to the Llama line, trained at Meta Superintelligence Labs.

Every edge in the DeepSeek tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• DeepSeek-Coder (Nov 2, 2023) — fine-tune of DeepSeek-LLM — DeepSeek-Coder shipped alongside the base LLM as a code-specialized fine-tune.
• DeepSeek-V2 (May 6, 2024) — new base of DeepSeek-LLM — DeepSeek-V2 paper introduced the DeepSeekMoE architecture and Multi-head Latent Attention as new base.
• DeepSeek-V3 (Dec 26, 2024) — new base of DeepSeek-V2 — DeepSeek-V3 paper introduced the 671B-parameter MoE as a new base.
• DeepSeek-R1 (Jan 20, 2025) — post-training of DeepSeek-V3 — DeepSeek-R1 paper documents R1 as RL post-training over the V3 base — RL-only emergent chain-of-thought.
• DeepSeek-V3.1 (Aug 21, 2025) — post-training of DeepSeek-V3
• DeepSeek-V3.2 (Dec 1, 2025) — post-training of DeepSeek-V3.1
• DeepSeek-V4-Pro (Apr 24, 2026) — new base of DeepSeek-V3.2 — DeepSeek-V4 introduced a new MoE base with Thinking and Non-Thinking modes.
• DeepSeek-V4-Flash (Apr 24, 2026) — distilled from of DeepSeek-V4-Pro — DeepSeek positioned V4-Flash as the smaller sibling shipped alongside V4-Pro.

Every edge in the Mistral tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• Mixtral 8x7B (Dec 11, 2023) — new base of Mistral 7B — Mixtral 8x7B introduced the sparse mixture-of-experts architecture as a new base, not a Mistral 7B fine-tune.
• Mistral Large (Feb 26, 2024) — new base of Mixtral 8x7B — Mistral Large was released as a proprietary flagship under the Mistral Research / commercial license, not a Mixtral fine-tune.
• Mistral Large 2 (Jul 24, 2024) — new base of Mistral Large
• Mistral Small 3 (Jan 30, 2025) — new base of Mistral Large 2 — Mistral Small 3 marked the December 2025 'Mistral 3' family relaunch under Apache 2.0 with new bases.
• Mistral Large 3 (Dec 2, 2025) — succession of Mistral Small 3
• Mistral Small 4 (Mar 16, 2026) — succession of Mistral Large 3

Every edge in the Qwen tree above, in chronological order. Each line shows: destination model, edge type, source model, and the provider documentation that establishes the relationship (where one was disclosed).

• Qwen-14B (Sep 25, 2023) — succession of Qwen-7B
• Qwen2 family (Jun 7, 2024) — new base of Qwen-14B — Qwen2 marked the June 2024 architecture refresh with the Apache 2.0 licensing turn for most variants.
• Qwen2.5 family (Sep 19, 2024) — post-training of Qwen2 family
• Qwen3 family (Apr 28, 2025) — new base of Qwen2.5 family — Qwen3 introduced the hybrid Thinking / Non-Thinking architecture, absorbing the standalone QwQ reasoning track.
• Qwen3-Max (Sep 15, 2025) — succession of Qwen3 family — Qwen3-Max is the largest Qwen3-generation flagship.
• Qwen3.5 + Plus (Feb 16, 2026) — succession of Qwen3-Max
• Qwen 3.6-Max (Apr 2, 2026) — succession of Qwen3.5 + Plus — Qwen 3.6-Max-Preview is the proprietary preview shipped alongside the open-weights 3.6 family.
• Qwen3.6-27B (Apr 22, 2026) — new base of Qwen3.5 + Plus — Qwen3.6-27B introduced the Gated DeltaNet + self-attention hybrid as a new base.