Apertus 1.5 adds image and audio input and a 262k context window

Apertus 1.5 extends the 8B and 70B Apertus 1.0 models with image and audio understanding, an optional thinking mode, and a context window of 262,144 tokens, four times the previous size.

The updated 8B and 70B weights were released on Hugging Face on July 24, 2026 under an Apache 2.0 license.

The source says the models still trail frontier open-weight models, with the 8B model outperforming similarly sized open-weight models on instruction-following and multilingual tasks.