Run 35B and 80B Qwen models on ordinary Apple devices, including iPhones.

Swiftlet is a Swift + Metal runtime for the Qwen3-Next and Qwen3.5/3.6 MoE hybrid model family. It keeps only the small dense core of a model resident in memory and streams the routed Mixture-of-Experts weights from storage on demand. The result:

Model Disk Peak RAM Decode speed (M5 Mac)

Qwen3.6-35B-A3B, 4-bit 18 GB 2.6 GB 7 to 11 tok/s

Qwen3-Next-80B-A3B, 4-bit 42 GB 4.3 GB 4.5 to 5 tok/s

The 35B also runs on an iPhone 17 in about 2.5 GB of RAM, at about 1 tok/s today. As far as we know, that is the first time a model of this class has run natively on a phone.

Status: working end to end. Both models generate correct, validated output. The current focus is kernel speed (the decode loop is dispatch bound, not IO bound, so there is clear headroom).…