Reference-scored browser ASRReport artifact2026-09-02

Parakeet WGSL Browser ASR

This closes the accuracy gap left by the original long-form smoke. On the frozen 34.365-second fixture, the official browser engine beat the native incumbent on WER, matched all four proper nouns, produced no repetition errors, and made no external warm requests. Its 33.84x median real-time factor is strong but below the preregistered 50x bar, so the formal decision remains reject rather than moving the goalposts.

WebGPU
browser
ASR
Apple Silicon
local first

Headline Numbers

Evidence class applies to each value: measured = retained evaluation or runtime result; historical = recorded result not freshly reproduced; derived = calculated or decided from records; observed = current artifact state; not-measured = an explicit evidence gap.

Browser WER

0.0%0/82 errors · eight test-clean clipsmeasured

Native WER

8.54%7/82 errors · identical clips and referencesmeasured

Paired latency

3.51x914.7ms browser · 3211.8ms nativemeasured

Short-clip RTFx

33.84xmedian · frozen gate required ≥50xmeasured

Competitive Context

System	Metric	Score	Size / Class	Comparable?	Readout
Parakeet TDT 0.6B v3 · browser	WER · total decode	0.0% · 914.7ms	684.4MB first download	Direct	Apple Metal WebGPU; zero warm external requests.
WhisperKit Mac-native baseline	WER · total decode	8.54% · 3211.8ms	1.5GB local Core ML model	Direct	Whisper large-v3 turbo; CPU and Neural Engine.

Direct rows share this artifact's eval setup. Directional rows are useful market context but should not be read as leaderboard claims.

Frozen promotion gates

Gate	Result	Decision
WER delta ≤2 points	−8.54 points	pass
Median warm RTFx ≥50	33.84x	fail
No repetition regression	0 vs 0	pass
Warm external requests	0	pass

Release Blockers

50x short-clip gate missed

The 2–7 second clips expose an approximately 80–100ms browser dispatch floor; median throughput reached 33.84x despite beating native latency by 3.51x.

Unblock: Do not change this decision. A separately frozen batching or long-form latency experiment may test whether fixed overhead amortizes.

Large optional first download

The pinned v3 browser model downloaded 684,385,250 bytes.

Unblock: Any product use must keep the download explicit, optional, and measured on Chrome and Safari.

Evidence

Next Release Action

Closed as a quality and native-latency win with a formal speed-threshold miss. Use it to teach paired evaluation, fixed-cost amortization, and why frozen gates matter.