The AI Museum
AI Analytics1,072 recordsRecounted 23 September 2026

Closed-weight language models in 2025

Weightsopenclosedunknownfrontier only
Year20262025202420232022202120202019201820172016
3 filters active, showing 33 of 1,072 recordsClear all

33

Models

12 organisations

0%

Open weights

0 open, 33 closed

3

Frontier

By Epoch's flag

560B

Largest traceable

Hunyuan-TurboS

2025

Span

3 with a traceable size

Releases

by month
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Organisation

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Domain

Records

33
Closed-weight language models in 2025, newest first. Each row links to the source Epoch AI records for it.
ModelOrganisationReleasedParametersWeights
GPT-5.2 CodexOpenAI2025-12—Closed
Claude Opus 4.5Anthropic2025-11—Closed
Gemini 3 Deep ThinkGoogle DeepMind2025-11—Closed
GPT-5.1-CodexOpenAI2025-11—Closed
GPT-5.1-Codex-MaxOpenAI2025-11—Closed
Grok 4.1xAI2025-11—Closed
Grok 4.1 FastxAI2025-11—Closed
Kaiju LargeCharacter.ai2025-11110B *Closed
Kaiju MediumCharacter.ai2025-1134B *Closed
Kaiju SmallCharacter.ai2025-1113B *Closed
Claude Haiku 4.5Anthropic2025-10—Closed
Claude Sonnet 4.5Anthropic2025-09—Closed
Qwen3-MaxAlibaba2025-091.0T *Closed
Claude Opus 4.1Anthropic2025-08—Closed
Gemini 2.5 Deep ThinkGoogle2025-08—Closed
Hierarchical Reasoning Model (HPM)Sapient Intelligence2025-0827MClosed
Gemini EmbeddingGoogle DeepMind2025-07—Closed
Grok 4xAI2025-073.0T *Closed
Grok 4 HeavyxAI2025-07—Closed
Gemini 2.5 Pro (Jun 2025)Google DeepMind2025-06—Closed
Claude Opus 4Anthropic2025-05—Closed
Claude Sonnet 4Anthropic2025-05—Closed
Gemini 2.5 Pro (May 2025)Google DeepMind2025-05—Closed
Pangu UltraHuawei2025-04135BClosed
Gemini 2.5 Pro (Mar 2025)Google DeepMind2025-03—Closed
Hunyuan-TurboSTencent2025-03560BClosed
o1-proOpenAI2025-03—Closed
Claude 3.7 SonnetAnthropic2025-02—Closed
GPT-4.5OpenAI2025-02—Closed
Grok 3xAI2025-023.0T *Closed
MercuryInception Labs2025-02—Closed
Doubao-1.5-proByteDance2025-01—Closed
o3-miniOpenAI2025-01—Closed

An asterisk marks a parameter figure the source does not consider traceable to the people who built the model. That judgement is the source’s and it has false negatives: Kimi K3 is marked speculative at 2.8T while Moonshot’s own model card states the figure. Why that distinction carries the whole exhibit.

Counts are of models Epoch AI records as notable, not of every model released. The most recent month is always incomplete, because a model enters the dataset when it is reviewed rather than when it ships.

Epoch AI, 'Data on AI Models'. Published online at epoch.ai. Retrieved from 'https://epoch.ai/data/ai-models-documentation' Used under CC BY 4.0.

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