Key Enhancements Training Process Multimodality Through the Tokenizer Pre-Training Post-Training Evaluation Results Evaluation Cards: Apertus ❤️ EvalEval Apertus 1.5 Reproducibility Model Availability How to Get Involved Citation Our latest release, Apertus 1.5, extends the 8B and 70B Apertus 1.0 models with image/audio understanding, an optional thinking mode, a four times longer context window, improved instruction-following, and better tool use. The updated 8B and 70B model weights were released to Hugging Face on July 24, 2026 under an Apache 2.0 license. Further details are now available from the project Technical Report, and summarized here.
Apertus 1.5 is a continued pretraining of the first generation model: adding 4 trillion tokens of text and multimodal training data to the 8B model and 2 trillion tokens to the 70B model, for a total of 19T and 17T, respectively. As with every Apertus release, the models are fully open: open weights, open data, open values, and full training details.
