2 models compared on the same benchmark — accuracy, latency, price, language coverage and capabilities. Universal-3 Pro leads on raw accuracy; GPT-4o Transcribe Diarize covers the most languages; Universal-3 Pro is cheapest.
Verdict · who wins what
Most accurate
Universal-3 Pro
13.5% WER
AssemblyAI
Fastest
—
—
Most languages
GPT-4o Transcribe Diarize
12 languages
OpenAI
Cheapest
Universal-3 Pro
$0.0035/min
AssemblyAI
Comparing
2 models · same benchmark
1
Universal-3 Pro
AssemblyAI
AssemblyAI's most powerful speech language model — up to 1000 keyterm phrases
2
GPT-4o Transcribe Diarize
OpenAI
GPT-4o transcription with built-in speaker diarization
30-day benchmark average
overall WER vs price
GPT-4o Transcribe Diarize
Universal-3 Pro
field · 23 models
lower-left is better
WER · lower is better
WER · English
p50 → p99
Streaming benchmark averages
Rolling 30 days
billed per second
Feature support
Languages · formats · regions
general
legal
medical
noisy
technical
uk
us
Latency p99
5.8s
18.1s
$20.88
$36.00
1,000 hours
$208.80
$360.00
No
Auto-detect language
Yes
Yes
Live / streaming
No
No
Custom vocabulary
Yes
No
Compliance
Is Universal-3 Pro or GPT-4o Transcribe Diarize more accurate?
Universal-3 Pro is more accurate, with a 13.5% word error rate versus 19.7% for GPT-4o Transcribe Diarize, on our standardized benchmark.
Which is cheaper, Universal-3 Pro or GPT-4o Transcribe Diarize?
Universal-3 Pro is cheaper at $0.0035/min versus $0.0060/min for GPT-4o Transcribe Diarize.
Should you choose Universal-3 Pro or GPT-4o Transcribe Diarize?
Choose Universal-3 Pro for accuracy and lower cost; choose GPT-4o Transcribe Diarize for language coverage.
