GPTNeo
GPTNeo is a model released by EleutherAI to try and provide an open source model with capabilities similar to OpenAI's GPT-3 model. One of the earliest such models, GPTNeo was trained on The Pile, Eleuther's corpus of web text.
A side-by-side comparison of release history, capabilities, licensing and model sizes.
| Attribute |
 GPTNeo
|
 Llama
|
|---|---|---|
| Developer | EleutherAI, Together | Meta |
| Current generation | – | Llama 4 |
| Initial release | 2021-03-21 | 2023-02-24 |
| Instruct tuned | No | Yes |
| Coding | No | Yes |
| Finetuning | Yes | Yes |
| Open source | Yes | Yes |
| License | Apache 2.0 | Llama Community License |
| Model sizes | 1.3B, 2.7B | 109B (17B active), 400B (17B active) |
| Links |
GPTNeo is a model released by EleutherAI to try and provide an open source model with capabilities similar to OpenAI's GPT-3 model. One of the earliest such models, GPTNeo was trained on The Pile, Eleuther's corpus of web text.
Llama is Meta's open-weight model family. Llama 4 was its last major generation; Meta's active assistant-model development has shifted to Muse.
Meta introduced LLaMA in February 2023, helping catalyze the modern open-weight model ecosystem. Llama 2 added commercial use and chat tuning, while the Llama 3 series improved scale, multilingual support, and instruction following. Llama 4, released in April 2025, introduced native multimodality and a mixture-of-experts architecture. Meta subsequently shifted its actively promoted assistant-model line to the proprietary Muse family, but Llama models remain widely used and deployed.