Skip to content

AssemblyAI · Audio

Universal-3.5 Pro API pricing

assemblyai/universal-3.5-pro

Speech-to-text. Universal-3.5 Pro by AssemblyAI, routed through INFRO on a AssemblyAI account you connect — alongside every other provider you run. AssemblyAI bills you for it directly, on that account and at your own rate. INFRO adds routing, failover, request logs, cost attribution and policy around it, and takes no part of what you pay AssemblyAI.

Pricing

Per audio hourUSD · updated 2026-10-05

AssemblyAI rate

$0.45

per audio hour, billed to you by AssemblyAI

INFRO adds

$0

0% markup on model spend

Calling Universal-3.5 Pro

POST /v1/audio/speech
import os
from infro import Infro

client = Infro(api_key=os.environ["INFRO_API_KEY"])

transcript = client.audio.transcriptions.create(
    model="assemblyai/universal-3.5-pro",
    file=open("meeting.mp3", "rb"),
)

What this modality supports

  • Text to speech
  • Music generation
  • Transcription
  • Diarization

Text-to-speech with streaming playback, full-track music generation, and transcription with timestamps and diarization. Billed per character generated, per track, and per hour transcribed.

QuickstartGet a key

Alternatives for speech-to-text

Same modality, nearest in price. All of them share the request shape above, so comparing them is a one-word change.

Work out what Universal-3.5 Pro would cost you

Put your current spend on this model into the calculator and see the same workload priced here — or have us read your real usage.

Price your workloadFree price estimate