Flan-UL2
Flan-UL2 is the independently released instruction-tuned UL2 update. Continued training extends the receptive field to 2048 tokens and removes the requirement for mode-switch tokens before Flan instruction tuning. The 20B T5-style encoder-decoder supports text-to-text generation, reasoning, and few-shot prompting. Google’s UL2 repository records checkpoint release on February 28, 2023, before later model-card and ecosystem announcements.
2023-02-28
20B
T5-style encoder-decoder Transformer with continued UL2 pretraining and Flan instruction fine-tuning
Apache-2.0
Specifications
- Parameters
- 20B
- Architecture
- T5-style encoder-decoder Transformer with continued UL2 pretraining and Flan instruction fine-tuning
- License
- Apache-2.0
- Context Window
- 2,048 tokens
- Type
- text
- Modalities
- text
Benchmark Scores
Advanced Specifications
- Model Family
- UL2
- Finetuned From
- ul2
- API Access
- Not Available
- Chat Interface
- Not Available
- Hardware Support
- GPUTPUCPU
Capabilities & Limitations
- Capabilities
- instruction followingtext-to-text generationreasoningfew-shot learning
- Known Limitations
- The 2048-token receptive field is short relative to modern long-context models.Reasoning answers can be incorrect and need verification.
- Notable Use Cases
- NLP researchreasoning experimentstext-task adaptation