Choosing a Model#

NeMo offers many pretrained speech models. This guide helps you pick the right one for your use case.

ASR: Which Model Should I Use?#

I want to…

Recommended Model

Why

Get the best accuracy on English

Canary-Qwen 2.5B

State-of-the-art English ASR. For very fast offline alternatives with almost SOTA accuracy, use Parakeet-TDT V2 or Parakeet-TDT V3.

Transcribe multiple languages

Canary-1B V2

Supports 25 EU languages + translation between them. AED decoder.

Transcribe European languages (ASR only, auto language detection)

Parakeet-TDT 0.6B V3

25 European languages in one model; automatic language detection; punctuation, capitalization, and word/segment timestamps; long-form and streaming options. No speech-to-text translation—use Canary-1B V2 if you need translation.

Stream audio in real-time

Nemotron-3.5-ASR-Streaming

Low-latency streaming ASR with 40 languages, controllable latency (80ms–1s), and configurable chunk sizes. Cache-aware FastConformer.

Minimize model size

Canary-180M Flash

Smallest multilingual model. Good for edge deployment.

Use CTC decoding (simpler pipeline)

Parakeet-CTC-1.1B

Non-autoregressive. Fast. Good with external language models.

Integrate with an external LM

Any Parakeet model + NGPU-LM

GPU-accelerated n-gram LM fusion for CTC, RNNT, and TDT models.

Transcribe multi-speaker meetings

Multitalker Parakeet Streaming

Handles overlapping speech in real-time with speaker-adapted decoding.

TTS: Which Model Should I Use?#

I want to…

Recommended Model

Why

Generate high-quality multilingual speech

MagpieTTS

End-to-end LLM-based TTS. Supports voice cloning and multiple languages.

Fast, controllable English synthesis

FastPitch + HiFi-GAN

Cascaded pipeline with pitch/duration control. Well-tested.

Generate discrete audio tokens

Audio Codec

Neural audio codec for tokenizing audio. Used by MagpieTTS internally.

Speaker Tasks: Which Model Should I Use?#

I want to…

Recommended Model

Why

Determine who spoke when

Streaming Sortformer, Offline Sortformer

End-to-end diarization for up to 4 speakers. Use streaming for real-time; use offline for batch.

Verify/identify a speaker

TitaNet

Extracts speaker embeddings for verification and identification.

Detect voice activity

MarbleNet

Frame-level VAD. Multilingual. Works as a preprocessing step.

Speech Language Models: Which Model Should I Use?#

I want to…

Recommended Model

Why

Ask questions about audio content

Canary-Qwen 2.5B (SALM)

LLM augmented with speech understanding. Can transcribe, translate, and answer questions about audio.

Build a speech-to-speech system

DuplexS2SModel

Full-duplex model that both understands and generates speech.

Where to Find Models#

All pretrained NeMo models are available on:

See Checkpoint Formats for instructions on loading pretrained models.