Whistle: a 16.9MB speech-to-text model that beats Whisper base at 9x smaller size and 6x speed

Henrie_the_dreamer · reddit · 2026-10-06

Cactus Compute released Cactus Whistle, an ASR model for ultra-small devices: 55M params (36M active), quantized to a 16.9MB file — 9x smaller than Whisper base (145.3MB) and 6x faster, while mostly beating it: 4.31 WER on LibriSpeech test-clean (vs 4.9), 10.49 on test-other, 21.4 FLEURS average (vs 24.5). It supports English, German, French, Spanish, Italian, Dutch, and Polish.

Architecture: log-mel front end + conv stem into an audio encoder; a Simple Attention + Hadamard MLP decoder with gated cross-attention, ladder-structured so any depth from 2 layers up is deployable. Keyword biasing favors user-specific names during beam search, and word timestamps come from decoder attention. It ships on 17 platforms including RISC-V, WebAssembly, and watchOS — the goal is compressing intelligence onto budget phones, wearables, and microcontrollers.

Related event: Tiny ASR Model Whistle Runs in Browsers at 16.9MB(2 posts)→

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