frontieropen-sourcemultimodal

01.AI (Yi)

High-quality multilingual open models from Kai-Fu Lee's pioneering AI startup.

4
Models tracked
2023
Founded
Yi-Large
Flagship model
Beijing
HQ
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About

About 01.AI (Yi)

01.AI was founded in 2023 by Kai-Fu Lee — legendary AI investor and former president of Google China — and has quickly built a reputation for strong open-source multilingual models. The Yi series is trained on a carefully curated bilingual English/Chinese dataset with emphasis on reasoning and long-context capability. Yi-34B-Chat supports a 200K token context window, and Yi-VL adds vision understanding.

01.ai

Key highlights

  • Founded by Kai-Fu Lee, one of the most respected figures in global AI

  • Yi-34B-Chat supports 200K token context — exceptional for a 34B open model

  • Strong bilingual English/Chinese capability across the full model family

  • All Yi models freely available on Hugging Face under the Yi Research Licence

  • Available via cloud API on Together AI, Fireworks AI, and other platforms

Models

4 models tracked

Context windows, pricing, capabilities, and API identifiers — everything you need to choose the right model for your workload.

Flagship

Yi-Large

2024

32Kcontext
TextCodeReasoning

01.AI's flagship commercial model. Strong multilingual reasoning and instruction following. Available through the 01.AI platform API.

  • Strong commercial quality
  • Bilingual English/Chinese
  • Complex reasoning
  • Tool use
In: $3 / M tokens
Out: $3 / M tokens
yi-large
Open Source

Yi-34B-Chat

2023

200Kcontext
TextCode

A 34B open-weight model with a remarkable 200K context window — the longest available in the class at its release. Strong bilingual performance for English and Chinese.

  • 200K context window
  • Open weights (Yi licence)
  • Bilingual excellence
  • Long document processing
yi-34b-chat
Open Source

Yi-VL-34B

2024

4Kcontext
TextVision

A 34B open-weight vision-language model. Handles complex image understanding and visual question answering tasks in both English and Chinese.

  • 34B vision-language model
  • Open weights
  • Image understanding
  • Bilingual VQA
yi-vl-34b
Open Source

Yi-1.5-34B-Chat

2024

4Kcontext
TextCode

Updated architecture over the original Yi series with improved instruction following, coding capability, and safety alignment. Open weights under the Yi licence.

  • Updated Yi architecture
  • Strong coding
  • Open weights
  • Broad inference support
yi-1.5-34b-chat

Use Cases

What 01.AI (Yi) is best for

Each provider has specialisms shaped by their architecture decisions, training data, and API design. Here is where 01.AI (Yi) performs best.

Chinese-English bilingual applications
Long-document analysis
Open-source AI research
Cost-efficient multilingual chatbots
Self-hosted reasoning systems

Get started

Start building with 01.AI (Yi)

Visit the official 01.AI (Yi) platform to access API keys, documentation, and pricing details.

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