Built for voice agents that can't wait 600ms

AssemblyAI: Universal-Streaming (English)

assemblyai/universal-streaming-english
active stt 1 provider
Playground

Ultra-fast (~300ms) English realtime speech-to-text built for voice agents.

AuthorAssemblyAI
Languages1 languages
Statusactive

Providers

Different providers can host the same model. Choose one provider when you need a fixed backend, or let routing select among them.

ProviderSlugPer hourLatencyiFor TTS, latency is measured as time to first byte of audio. For STT, latency is measured as time to first token.ModesUptime
AssemblyAI 13 params
assemblyai
$0.15
—
Streaming

Supported languages

1 languages
English en

Features

Speech to text

Transcribes spoken audio to text.

speech_to_text
Streaming

Real-time streaming transcription over WebSocket.

streaming
Multilingual transcription

English only.

multilingual_transcription
Speaker diarization

Identifies and labels multiple speakers.

speaker_diarization
Word-level timestamps

Returns word-level timestamps.

word_timestamps

Code

Client
Mode
Language

ElevenLabs SDK streaming STT

Streams microphone or file audio through the ElevenLabs-compatible allmodels route.

import { ElevenLabsClient } from "elevenlabs";

const client = new ElevenLabsClient({
  apiKey: process.env.ALLMODELS_API_KEY,
  baseUrl: "https://api.allmodels.io/el"
});

const connection = await client.speechToText.realtime.connect({
  modelId: "assemblyai/universal-streaming-english",
  languageCode: "en"
}, {
  queryParams: {
    provider: {
      "only": [
        "assemblyai"
      ]
    }
  }
});

// Send audio frames to connection, then handle transcript events.