Model reference · open weights

parakeet-ctc

Audio nvidia Speech→text 2 builds Open weights 1.7M dl/mo

parakeet-ctc is an open-weight audio or speech model from NVIDIA. parakeet-ctc-0.6b (FP32) weighs 1.2 GB; the smallest configuration that runs it is RTX 3060 12 GB.

  • parakeet-ctc-1.1b is an automatic speech recognition model developed by NVIDIA and Suno.ai that transcribes English speech into lower case text.
  • The model features 1.1 billion parameters and is based on the FastConformer architecture.
  • It accepts 16000 Hz mono-channel audio input and is released under the CC-BY-4.0 license.

Summary of the nvidia/parakeet-ctc-1.1b model card, 2026-10-01. The estimate below is for another build of the family.

What it is

Released byNVIDIA
Released2023-12-28
Parameters1.1B
VRAM1.2 GB for the weights

What it runs on

Memory and cards for parakeet-ctc-0.6b (FP32)

1.2 GBweights, file size
1.6 GBruntime overhead
CardOne streamMemory
RTX 3060 12 GBfits11.6 GB
RTX 4060 Ti 16 GBfits15.4 GB
RTX 3090 24 GBfits23.4 GB
RTX 4090 24 GBfits23.4 GB
RTX 5090 32 GBfits31.0 GB
L40S 48 GBfits44.0 GB
A100 80 GBfits78.2 GB
H100 80 GBfits78.1 GB
RTX PRO 6000 Blackwell 96 GBfits93.8 GB
DGX Spark (GB10) 128 GB unifiedfits107 GB
H200 141 GBfits138 GB
B200 180 GBfits176 GB

Builds

Sizes, precisions & builds

BuildParamsPrecisionWeightsSmallest setup
parakeet-ctc-1.1b ↗ 1.1BFP32 1.2 GBRTX 3060 12 GB
parakeet-ctc-0.6b (above) ↗ 609MFP32 1.2 GBRTX 3060 12 GB

From the model card

What NVIDIA says about parakeet-ctc

Read the model card

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parakeet-ctc-1.1b is an ASR model that transcribes speech in lower case English alphabet. This model is jointly developed by NVIDIA NeMo and Suno.ai teams. It is an XXL version of FastConformer CTC [1] (around 1.1B parameters) model. See the model architecture section and NeMo documentation for complete architecture details.

NVIDIA NeMo: Training

To train, fine-tune or play with the model you will need to install NVIDIA NeMo. We recommend you install it after you've installed latest PyTorch version.

pip install nemo_toolkit['all']

How to Use this Model

There are several ways to use this model. Choose the one that fits your needs.

Run locally with NeMo-Speech.cpp

NeMo-Speech.cpp provides a lightweight native C++ runtime for local inference with this model. After installing the runtime:

hf download nvidia/parakeet-ctc-1.1b \
  parakeet-ctc-1.1b.q8_0.gguf \
  --local-dir models

nemo-speech transcribe audio.wav \
  --model models/parakeet-ctc-1.1b.q8_0.gguf

See the NeMo-Speech.cpp documentation for more details.

NVIDIA NeMo

The model is available for use in the NeMo toolkit [3], and can be used as a pre-trained checkpoint for inference or for fine-tuning on another dataset. Moreover, you can now run Parakeet CTC natively with Transformers 🤗.

Automatically instantiate the model
import nemo.collections.asr as nemo_asr
asr_model = nemo_asr.models.EncDecCTCModelBPE.from_pretrained(model_name="nvidia/parakeet-ctc-1.1b")
Transcribing using NeMo

First, let's get a sample

wget https://dldata-public.s3.us-east-2.amazonaws.com/2086-149220-0033.wav

Then simply do:

asr_model.transcribe(['2086-149220-0033.wav'])

Transcribing using Transformers 🤗

Make sure to install transformers from source.

pip install git+https://github.com/huggingface/transformers
from transformers import pipeline

pipe = pipeline("automatic-speech-recognition", model="nvidia/parakeet-ctc-1.1b")
out = pipe("https://huggingface.co/datasets/hf-internal-testing/dummy-audio-samples/resolve/main/bcn_weather.mp3")
print(out)
from transformers import AutoModelForCTC, AutoProcessor
from datasets import load_dataset, Audio
import torch

device = "cuda" if torch.cuda.is_available() else "cpu"

processor = AutoProcessor.from_pretrained("nvidia/parakeet-ctc-1.1b")
model = AutoModelForCTC.from_pretrained("nvidia/parakeet-ctc-1.1b", dtype="auto", device_map=device)

ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation")
ds = ds.cast_column("audio", Audio(sampling_rate=processor.feature_extractor.sampling_rate))
speech_samples = [el['array'] for el in ds["audio"][:5]]

inputs = processor(speech_samples, sampling_rate=processor.feature_extractor.sampling_rate)
inputs.to(model.device, dtype=model.dtype)
outputs = model.generate(**inputs)
print(processor.batch_decode(outputs))
from transformers import AutoModelForCTC, AutoProcessor
from datasets import load_dataset, Audio
import torch

device = "cuda" if torch.cuda.is_available() else "cpu"

processor = AutoProcessor.from_pretrained("nvidia/parakeet-ctc-1.1b")
model = AutoModelForCTC.from_pretrained("nvidia/parakeet-ctc-1.1b", dtype="auto", device_map=device)

ds = load_dataset("hf-internal-testing/librispeech_asr_dummy", "clean", split="validation")
ds = ds.cast_column("audio", Audio(sampling_rate=processor.feature_extractor.sampling_rate))
speech_samples = [el['array'] for el in ds["audio"][:5]]
text_samples = [el for el in ds["text"][:5]]

# passing `text` to the processor will prepare inputs' `labels` key
inputs = processor(audio=speech_samples, text=text_samples, sampling_rate=processor.feature_extractor.sampling_rate)
inputs.to(device, dtype=model.dtype)

outputs = model(**inputs)
outputs.loss.backward()

For more details about usage, the refer to Transformers' documentation.

Transcribing many audio files

python [NEMO_GIT_FOLDER]/examples/asr/transcribe_speech.py
 pretrained_name="nvidia/parakeet-ctc-1.1b"
 audio_dir=""

Input

This model accepts 16000 Hz mono-channel audio (wav files) as input.

Output

This model provides transcribed speech as a string for a given audio sample.

Model Architecture

FastConformer [1] is an optimized version of the Conformer model with 8x depthwise-separable convolutional downsampling. The model is trained using CTC loss. You may find more information on the details of FastConformer here: Fast-Conformer Model.

Training

The NeMo toolkit [3] was used for training the models for over several hundred epochs. These model are trained with this example script and this base config.

The tokenizers for these models were built using the text transcripts of the train set with this script.

Datasets

The model was trained on 64K hours of English speech collected and prepared by NVIDIA NeMo and Suno teams.

The training dataset consists of private subset with 40K hours of Eng

Quoted from the model card on Hugging Face. The full card is behind the Hugging Face link above.

Benchmarks

Reported results

As published on the model card: the maker's own numbers, not measured by AxForge.

TaskDatasetMetricScore
Automatic Speech RecognitionAMI (Meetings test)Test WER15.620
Automatic Speech RecognitionEarnings-22Test WER13.690
Automatic Speech RecognitionGigaSpeechTest WER10.270
Automatic Speech RecognitionLibriSpeech (clean)Test WER1.830
Automatic Speech RecognitionLibriSpeech (other)Test WER3.540
automatic-speech-recognitionSPGI SpeechTest WER4.200
automatic-speech-recognitiontedlium-v3Test WER3.540
Automatic Speech RecognitionVox PopuliTest WER6.530
automatic-speech-recognitionMozilla Common Voice 9.0Test WER9.020
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