Yi-34B
Kai-Fu Lee's 01.AI bilingual flagship: 34B trained from scratch, open weights.
About
Yi-34B is the flagship base model of 01.AI, the Chinese AI company founded by Kai-Fu Lee, released on November 2, 2023. Trained from scratch on a 3-trillion-token multilingual corpus (not a LLaMA derivative, despite early speculation), it is a bilingual English-Chinese 34B model that was briefly among the strongest open models of its generation — scoring around 76-78% on MMLU at release.
The family grew quickly: Yi-34B-Chat arrived November 23, 2023, followed by 200K-context variants (Yi-34B-200K) via NTK-aware RoPE scaling, and smaller Yi-6B/Yi-9B siblings. 01.AI later expanded into Yi-Coder and other specialized models.
License nuance: the Yi series ships under the Yi Community License Agreement (custom terms), not Apache 2.0 as some aggregators claim — read the actual MODEL_LICENSE_AGREEMENT before commercial use. As a 2023-era model it is now far behind the frontier, but it remains an important reference point in Chinese open-model history.
Specs
Context window
Pricing
Free quota
API access
Weights
Released
Benchmarks
Provider-reported unless a source says otherwise. Benchmarks are marketing-adjacent by nature — treat them as directional.
Use cases
Trust score — 6/10
Scored 6/10 (metrics tier, metrics-v1). Evidence: Verified via vendor site/docs/GitHub and reputable coverage, wave 76; Trending score 64/100 from researcher assessment.