TinyComma 1.8B is a 1.8B parameter, decoder-only base LM trained entirely on permissively licensed data from the Common Pile. Different from the official Comma model series, TinyComma 1.8B uses the 128K-vocabulary Llama3 tokenizer to ensure compatibility with two-model decoding setups.
We trained TinyComma 1.8B to support our research on inference-time copyright mitigation.
We benchmarked TinyComma 1.8B and several other permissively trained base models on several common natural language understanding tasks from the OLMES evaluation suite.
Benchmarking results using OLMES. TinyComma 1.8B outperforms other models of its size range.
Training details
We trained TinyComma 1.8B using the lingua training framework. Pre-training consists of two stages: (1) a 156B-token generation training stage over the entire Common Pile, following original domain weights specified by Kandpal et al., 2025,
and (2) a 13.5B-token cooldown stage on a weighted mixture of three high-quality domains (70% Wikimedia, 15% DOAB, and 15% Data Provenance Initiative data). Our hardware is a single node of 8 140 GiB H200 GPUs. Model configuration and pre-training hyperparameter details are below:
TinyComma 1.8B model configuration.
Params
Head Dim.
Hidden Size
Attn. Heads
Hidden Layers
KV Heads
1,758,562,304
64
2048
32
24
32
TinyComma 1.8B pretraining configuration.
Hyperparameters
Values
Optimizer
AdamW (β1=0.9, β2=0.95)
Learning rate
3e−3 for Stage 1, 1e−3 for Stage 2
Weight decay
0.033 for Stage 1
Batch size
4M tokens
Warmup
1000 steps for Stage 1, none for Stage 2
Schedule
Cosine schedule for Stage 1, linear schedule for Stage 2
Sequence length
Pack to 2048 tokens
Citation
@article{he2026anchored,title={{Anchored Decoding: Provably Reducing Copyright Risk for Any Language Model}},author={Jacqueline He and Jonathan Hayase and Wen-tau Yih and Sewoong Oh and Luke Zettlemoyer and Pang Wei Koh},journal={arXiv preprint},year={2026}}