Baidu releases ERNIE 5.5 Flash Base, a 280B open-weight model barred from EU and UK use

What Baidu released

Baidu published ERNIE 5.5 Flash Base on 5 November 2026 on Hugging Face and ModelScope, with weights in FP8 and BF16. The model card lists a mixture of experts architecture with 280 billion total parameters, of which 14 billion are active for each token, which keeps inference costs closer to those of a mid-sized dense model. Baidu says it was pretrained from scratch on 33.5 trillion tokens with a training context of up to 128,000 tokens, which can be extended to 1 million tokens for fine-tuning and inference.

This is a base model. Baidu describes it as the checkpoint taken at the end of pre-training, before any mid-training or post-training, so it has not been tuned to follow instructions or chat. It is meant for teams that want to run their own fine-tuning, distillation or reinforcement learning on top of a large pretrained network. Baidu publishes benchmark comparisons with other base models, including DeepSeek's Flash base model, but those are its own runs and have not been independently reproduced.

A license with territorial limits

The weights are free to download but not free to use everywhere. The ERNIE 5.5 Flash Base Model License Agreement v1.0 defines the licensed territory as "all geographical areas worldwide other than the European Union, the United Kingdom and South Korea", as quoted by Trending Topics and other outlets that read the license. The restriction concerns where the model is used, adapted or distributed, not only where a company is based.

Commercial use is allowed without a fee when the related annual revenue is $50 million or less, provided the user sends Baidu a one-time notice and shows a "Powered by ERNIE" notice. Above $50 million, a separate written commercial license from Baidu is required in advance. The license also forbids using the weights, derivatives or outputs to improve AI systems other than ERNIE and its derivatives, which rules out using the model to generate training data for a competing model. Research and other non-commercial use is free.

That is a sharp change from ERNIE 4.5, which Baidu released under the permissive Apache 2.0 license in 2025. The new terms resemble the custom licenses that Meta, Moonshot AI and others attach to large open-weight models, but the exclusion of three jurisdictions is unusual. Baidu has not explained it. In the EU, providers of general-purpose AI models already carry obligations under the EU AI Act, including documentation and copyright policies, and a territorial carve-out is one way for a provider to avoid placing a model on that market.

Where it fits

Chinese labs have released a steady stream of large open-weight models this autumn, including Moonshot AI's Kimi K3.1 Pro and DeepSeek's V4.1-Flash update, most of them as finished instruction-tuned models. A large base checkpoint is rarer and more useful to researchers and companies that want to control post-training themselves, since instruction tuning can hide or remove capabilities.

For developers in the excluded regions the release changes little: they can read the model card but cannot legally deploy or adapt the model. Elsewhere, the questions are practical. Running a 280 billion parameter model needs multi-GPU servers even with only 14 billion parameters active, because all experts must sit in memory. Baidu has not given a date for a post-trained version of ERNIE 5.5 Flash. The release is listed in our model release tracker, and other open-weight releases are on the open-source AI page.

Questions people ask

Can ERNIE 5.5 Flash Base be used in the EU or UK?

No. Its license defines the licensed territory as every region except the European Union, the United Kingdom and South Korea.

Is ERNIE 5.5 Flash Base free for commercial use?

Yes up to $50 million in related annual revenue, with a one-time notice to Baidu and a Powered by ERNIE notice. Above that a separate written license is required.

Is ERNIE 5.5 Flash Base a chat model?

No. It is a pretrained base checkpoint taken before mid-training and post-training, intended for further training by developers.

Sources

1. baidu/ERNIE-5.5-Flash-Base (Baidu (Hugging Face), 5 Nov 2026)
2. ERNIE 5.5 Flash Base (Baidu, 5 Nov 2026)
3. Baidu Releases ERNIE 5.5 Flash Base: A 280B MoE Base Model With 14B Active Parameters (MarkTechPost, 5 Nov 2026)
4. ERNIE 5.5 Flash Base: Baidu's New Open-Weight Model May Not Be Used in the EU (Trending Topics, 6 Nov 2026)
5. Baidu Releases ERNIE 5.5 Flash Base for Further Training (Unite.AI, 6 Nov 2026)