Qwen3-ASR

Alibaba's Qwen3-ASR family ported to transcribe.cpp. An audio-LLM design: a bidirectional audio encoder feeds audio tokens into a Qwen3 causal LM that emits the transcript autoregressively. Both shipped variants share the contract — 16 kHz mono PCM in, transcript text out — and auto-detect across 30 languages.

For the architecture deep-dive, validation contract, and porting notes, see the family doc at docs/porting/families/qwen3_asr.md.

Choosing a variant

• Smaller, faster, near-realtime CPU. qwen3-asr-0.6b — 600M parameters, 811 MB at Q8_0. 18-layer encoder + Qwen3 LM with hidden_size=1024. ~2.1% WER on LibriSpeech test-clean.
• Accuracy headroom. qwen3-asr-1.7b widens both halves of the model (24-layer encoder, LM hidden_size=2048, intermediate_size=6144) for ~0.5pp WER improvement at ~2.5× the storage and decode cost.
• Language coverage is identical across the two variants — pick on the accuracy/cost axis, not on languages.

All variants

WER is on LibriSpeech test-clean for the Q8_0 preset, measured by transcribe.cpp's WER pipeline. See each per-variant doc for the full quant matrix.

Variant	Params	Q8_0 size	WER (Q8_0)	Languages	Doc
qwen3-asr-0.6b	~600M	811 MB	2.11%	30 (auto-detect)	qwen3-asr-0.6b.md
qwen3-asr-1.7b	~1.7B	2.08 GB	1.61%	30 (auto-detect)	qwen3-asr-1.7b.md

Pre-built GGUFs for every variant and quant are hosted under handy-computer on Hugging Face; each per-variant doc has direct download links.

Input limits

Both variants accept up to about 87 minutes of 16 kHz mono audio in a single call — the binding limit is the 65,536-token decoder context, shared across the family. That ceiling is there to bound memory and sits far beyond any normal clip; audio past it is rejected up front with TRANSCRIBE_ERR_INPUT_TOO_LONG rather than silently truncated. Lowering --n-ctx lowers the limit (and the KV-cache footprint), and transcribe_session_get_limits() reports the exact per-session value. See the input-length contract.

Quick start

Pick a variant and run:

cmake -B build
cmake --build build

build/bin/transcribe-cli \
  -m models/qwen3-asr-0.6b/qwen3-asr-0.6b-Q8_0.gguf \
  samples/jfk.wav

The repo doesn't ship the GGUFs — pull them from the corresponding handy-computer/<variant>-gguf repo on Hugging Face, or convert from the upstream Qwen checkpoint via the per-variant doc's reproduction section.

Capabilities

All Qwen3-ASR variants support:

• Transcription of 16 kHz mono WAV input.
• Auto language detection across 30 languages.

What's not supported (consistent across the family): translation, real-time streaming, VAD, speaker diarization, timestamps. See the family doc for the full runtime contract.