Inference APIs
Compare/Speech-to-text

Whisper Large v3 vs AssemblyAI Universal

Whisper Large v3 is an open-weight speech-to-text model you can call on this endpoint; AssemblyAI Universal is a closed model from AssemblyAI. Below: what each costs for three realistic workloads, the limits that apply, and when to choose which.

AssemblyAI figures are public list prices and documented limits, checked 2026-09-16 against the provider page. Inference APIs prices are read live from the price list.

Short answer
  • Cost: Whisper Large v3 is cheaper in all three workloads, by 20%.
  • Limits: AssemblyAI: Concurrency limits by plan. Here: no per-minute or per-day caps.

Side by side

Whisper Large v3AssemblyAI Universal
Served byInference APIsAssemblyAI
Model authorOpenAIAssemblyAI
Model idopenai/whisper-large-v3universal
Price$0.002 / audio minute$0.0025 / audio minute
CapabilitiesSpeech to text, 100 languages, Word timestamps, Speaker diarization, SRT / VTTSpeech to text, Diarization, Speech understanding
WeightsOpenClosed
StatusAvailableAvailable
LimitsNo per-minute or per-day request or token caps; usage draws on a prepaid balanceConcurrency limits by plan.
Speed0.047× real time (19.5 s clip in 0.92 s)not measured by us

What three workloads cost

List prices applied to the same work. The cheaper side of each row is in bold.

WorkloadWhisper Large v3AssemblyAI UniversalDifference
1 hour of audio$0.12$0.1520%
100 hours of audio$12.00$15.0020%
1,000 hours of audio$120$15020%

Whisper Large v3 is cheaper in all three workloads, by 20%.

When to choose which

Choose Whisper Large v3 if
  • Cost is the deciding factor; it is cheaper in every workload above
  • You want open weights: the same model can be moved to another host or self-hosted later
  • Broad language coverage with automatic language detection
  • Files up to 100 MB and SRT or VTT subtitles straight from the API
  • Speaker labels with diarize=true, at the same price
  • You need an OpenAI-compatible endpoint; its API has its own request format
Choose AssemblyAI Universal if
  • You need speaker diarization
  • You want built-in summaries, sentiment or PII redaction on top of the transcript

Measured speed

Median of three runs on 2026-09-16: a 19.5-second mp3 clip, timed from upload to response. Expect ±30% with time of day. We did not measure AssemblyAI and do not quote other people's numbers; read "not measured" as unknown, not slow. Method and raw numbers: speed measurements.

FAQ

Which is cheaper, Whisper Large v3 or AssemblyAI Universal?

Whisper Large v3 is cheaper in all three workloads, by 20%. The table above uses list prices: Whisper Large v3 $0.002 / audio minute; AssemblyAI Universal $0.0025 / audio minute.

What limits apply to AssemblyAI Universal?

Concurrency limits by plan. On Inference APIs there are no per-minute or per-day request or token caps; usage draws on a prepaid balance.

Spotted a price or limit that has changed? Tell us and we will re-check the provider page.