2 models compared on the same benchmark — accuracy, latency, price, language coverage and capabilities. Soniox STT (Async) leads on raw accuracy; Soniox STT (Async) is fastest; Soniox STT (Async) covers the most languages; Soniox STT (Async) is cheapest.
Verdict · who wins what
Most accurate
Soniox STT (Async)
8.7% WER
Soniox
Fastest
Soniox STT (Async)
0.1× realtime
Soniox
Most languages
Soniox STT (Async)
25 languages
Soniox
Cheapest
Soniox STT (Async)
$0.0017/min
Soniox
Comparing
2 models · same benchmark
1
Universal-3.5 Pro Realtime
AssemblyAI
AssemblyAI Universal-3.5 Pro Realtime — the flagship streaming model, with native mid-sentence code-switching across 18 languages and conversation context carried across turns. Word-level timestamps and stable partials that are not rewritten as they arrive; speaker diarization is available on the batch model, not this streaming one.
2
Soniox STT (Async)
Soniox
Soniox async batch transcription — one multilingual model across 60+ languages with speaker diarization, per-word timestamps, and automatic language identification, at a low flat token-based rate.
general
—
legal
—
medical
—
noisy
—
technical
—
uk
—
us
—
—
6.2s
Final drain
109ms
—
Real-time factor
1.02×
—
Flicker
15.7%
—
Cadence
0.8/s
—
$10.08
1,000 hours
$450.00
$100.80
No
Auto-detect language
Yes
Yes
Live / streaming
Yes
No
Custom vocabulary
No
No
Max file size
5 GB
No limit
Max duration
10 h
5 h
Compliance
—
Is Universal-3.5 Pro Realtime or Soniox STT (Async) more accurate?
Soniox STT (Async) has a published benchmark at 8.7% word error rate. Universal-3.5 Pro Realtime has not been benchmarked yet.
Which is cheaper, Universal-3.5 Pro Realtime or Soniox STT (Async)?
Soniox STT (Async) is cheaper at $0.0017/min versus $0.0075/min for Universal-3.5 Pro Realtime.
Should you choose Universal-3.5 Pro Realtime or Soniox STT (Async)?
Soniox STT (Async) is the stronger choice overall, leading on accuracy, speed, lower cost, and language coverage.
