DeepSeek vs. Pythia

DeepSeek

DeepSeek develops open-weight mixture-of-experts models for reasoning, coding, agents, and efficient long-context inference. DeepSeek V4 is the current generation.

DeepSeek began releasing language models in 2023 with DeepSeek Coder, then gained broad adoption with DeepSeek V3 and the R1 reasoning model in 2024 and 2025. DeepSeek V4, released in April 2026, includes a 284B-parameter Flash model with 13B active parameters and a 1.6T-parameter Pro model with 49B active parameters. Both support one-million-token context windows and are released with open weights under the MIT license.

Further reading

• api-docs.deepseek.com/news/news260424/
• huggingface.co/collections/deepseek-ai/deepseek-v4

Pythia

The most recent (as of May 2023) effort from EleutherAI, Pythia is a set of LLMs trained on The Pile. While it appears to outperform OPT and GPTNeo, its performance against GPT-J is unclear. Versions of Pythia have also been instruct-tuned by the team at Together.