C4 is a colossal, cleaned version of Common Crawl's web crawl corpus. It was based on Common Crawl dataset: https://commoncrawl.org. It was used to train the T5 text-to-text Transformer models.

The dataset can be downloaded in a pre-processed form from allennlp.

C4 tiny

this dataset is a very small subset of https://huggingface.co/datasets/allenai/c4 that can be use for testing without having to download the full c4 dataset. to use from dataset import load_dataset dataset = load_dataset("PrimeIntellect/c4-tiny", "en", ignore_verifications=True)

The C4 DatabaseThis is the official repository for the hdf5 datasets of the cerebellar cell-type classification collaboration (C4), published as a companion to the paper "A deep-learning strategy to identify cell types across species from high-density extracellular recordings" published in Cell (https://doi.org/10.1016/j.cell.2025.01.041).Instructions to use the cell-type classifier, links to download these datasets, and a data explorer can be found at https://www.c4-database.com.The specifications of the fields, data types and data formats stored in the hdf5 binary files can be found at https://www.tinyurl.com/c4database. Hdf5 files can be easily opened with Python, MATLAB and many other programming languages.Using and Citing the C4 DatabaseThe data and visualizations on this website are intended to be freely available for use by the scientific community. The C4 dataset is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, while our classifier is licensed under the GNU General Public License v3.0 as part of NeuroPyxels. If you download and use our data for a publication, and/or if you would like to refer to the database, please cite Beau et al., 2025, Cell together with the NeuroPyxels repository (Beau et al., 2021, Zenodo), and include the link to the C4 online portal https://www.c4-database.com in your methods section. Thank you!

This is a small subset representing the first 10K records of the original C4 dataset, "en" subset - created for testing. The records were extracted after having been shuffled.

The full 1TB+ dataset is at https://huggingface.co/datasets/c4.

C4 0140

## Overview

C4 0140 is a dataset for object detection tasks - it contains JF2010 01D annotations for 395 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [CC BY 4.0 license](https://creativecommons.org/licenses/CC BY 4.0).

A medical abbreviation expansion dataset which applies web-scale reverse substitution (wsrs) to the C4 dataset, which is a colossal, cleaned version of Common Crawl's web crawl corpus.

The original source is the Common Crawl dataset: https://commoncrawl.org

To use this dataset:

import tensorflow_datasets as tfds

ds = tfds.load('c4_wsrs', split='train')
for ex in ds.take(4):
 print(ex)

See the guide for more informations on tensorflow_datasets.

SL Abhi C4

## Overview

SL Abhi C4 is a dataset for object detection tasks - it contains Face annotations for 371 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [CC BY 4.0 license](https://creativecommons.org/licenses/CC BY 4.0).

'C1''C2''C3' 'C4' 'C5' 'C6'

## Overview

'C1''C2''C3' 'C4' 'C5' 'C6' is a dataset for semantic segmentation tasks - it contains Car annotations for 1,000 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [Public Domain license](https://creativecommons.org/licenses/Public Domain).

mC4 is a multilingual variant of the C4 dataset called mC4. mC4 comprises natural text in 101 languages drawn from the public Common Crawl web scrape.

C4 0125(CY1793 02D)

## Overview

C4 0125(CY1793 02D) is a dataset for object detection tasks - it contains C4 0125 annotations for 989 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [CC BY 4.0 license](https://creativecommons.org/licenses/CC BY 4.0).

BUS_nocard

## Overview

BUS_nocard is a dataset for object detection tasks - it contains Bus GzEj annotations for 3,603 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [CC BY 4.0 license](https://creativecommons.org/licenses/CC BY 4.0).

M3 Fruit Classification

## Overview

M3 Fruit Classification is a dataset for object detection tasks - it contains Fruits annotations for 2,306 images.

## Getting Started

You can download this dataset for use within your own projects, or fork it into a workspace on Roboflow to create your own model.

  ## License

  This dataset is available under the [CC BY 4.0 license](https://creativecommons.org/licenses/CC BY 4.0).