Open models narrow gap as Europe pushes sovereignty

Mozilla’s September 2026 assessment frames open-source and open-weight AI as a maturing part of the global AI ecosystem, helped by improving capability, lower costs, and greater control over deployment. Mozilla CTO Raffi Krikorian points to European work such as a Lausanne medical model built with the Red Cross and tuned to humanitarian guidelines.

Adoption signals are strong: Hugging Face hosts 2.5 million public models, has 13 million users, and reaches a third of the Fortune 500. On OpenRouter, open-weight models grew to roughly a third of usage by late 2025, and six months later the platform was moving 25 trillion tokens a week, with an open model as its largest traffic source.

Europe is active in open AI but not leading at the frontier. The strongest open models assessed are largely Chinese, including Kimi K3, GLM-5.3, and Qwen 3.8, while Mistral Medium 3.5 appears further down the capability spectrum and carries commercial restrictions.

The larger European opening may be deployment. Globally, 79 per cent of surveyed developers use open models, but only 51 per cent of open-model users reach production, compared with 63 per cent for closed models. The UK is backing Lumen Sovereign through the £500 million Sovereign AI programme, targeting more than 30 regulated workflows and air-gapped deployment by the end of 2026, while Mozilla warns that the EU AI Act’s compute-based risk proxy may struggle to track more efficient models.