Datasets:
c4

	---
	pretty_name: C4
	annotations_creators:
	- no-annotation
	language_creators:
	- found
	language:
	- en
	license:
	- odc-by
	multilinguality:
	- multilingual
	size_categories:
	- 100M<n<1B
	source_datasets:
	- original
	task_categories:
	- text-generation
	- fill-mask
	task_ids:
	- language-modeling
	- masked-language-modeling
	paperswithcode_id: c4
	viewer: false
	dataset_info:
	- config_name: en
	features:
	- name: text
	dtype: string
	- name: timestamp
	dtype: string
	- name: url
	dtype: string
	splits:
	- name: train
	num_bytes: 828589180707
	num_examples: 364868892
	- name: validation
	num_bytes: 825767266
	num_examples: 364608
	download_size: 326778635540
	dataset_size: 1657178361414
	- config_name: en.noblocklist
	features:
	- name: text
	dtype: string
	- name: timestamp
	dtype: string
	- name: url
	dtype: string
	splits:
	- name: train
	num_bytes: 1029628201361
	num_examples: 393391519
	- name: validation
	num_bytes: 1025606012
	num_examples: 393226
	download_size: 406611392434
	dataset_size: 2059256402722
	- config_name: realnewslike
	features:
	- name: text
	dtype: string
	- name: timestamp
	dtype: string
	- name: url
	dtype: string
	splits:
	- name: train
	num_bytes: 38165657946
	num_examples: 13799838
	- name: validation
	num_bytes: 37875873
	num_examples: 13863
	download_size: 15419740744
	dataset_size: 76331315892
	- config_name: en.noclean
	features:
	- name: text
	dtype: string
	- name: timestamp
	dtype: string
	- name: url
	dtype: string
	splits:
	- name: train
	num_bytes: 6715509699938
	num_examples: 1063805381
	- name: validation
	num_bytes: 6706356913
	num_examples: 1065029
	download_size: 2430376268625
	dataset_size: 6722216056851
	---

	<div class="course-tip course-tip-orange bg-gradient-to-br dark:bg-gradient-to-r before:border-orange-500 dark:before:border-orange-800 from-orange-50 dark:from-gray-900 to-white dark:to-gray-950 border border-orange-50 text-orange-700 dark:text-gray-400">
	<p><b>Deprecated:</b> Dataset "c4" is deprecated and will be deleted. Use "<a href="https://huggingface.co/datasets/allenai/c4">allenai/c4</a>" instead.</p>
	</div>

	# Dataset Card for C4

	## Table of Contents

	- [Dataset Card for C4](#dataset-card-for-c4)
	- [Table of Contents](#table-of-contents)
	- [Dataset Description](#dataset-description)
	- [Dataset Summary](#dataset-summary)
	- [Supported Tasks and Leaderboards](#supported-tasks-and-leaderboards)
	- [Languages](#languages)
	- [Dataset Structure](#dataset-structure)
	- [Data Instances](#data-instances)
	- [Data Fields](#data-fields)
	- [Data Splits](#data-splits)
	- [Dataset Creation](#dataset-creation)
	- [Curation Rationale](#curation-rationale)
	- [Source Data](#source-data)
	- [Initial Data Collection and Normalization](#initial-data-collection-and-normalization)
	- [Who are the source language producers?](#who-are-the-source-language-producers)
	- [Annotations](#annotations)
	- [Annotation process](#annotation-process)
	- [Who are the annotators?](#who-are-the-annotators)
	- [Personal and Sensitive Information](#personal-and-sensitive-information)
	- [Considerations for Using the Data](#considerations-for-using-the-data)
	- [Social Impact of Dataset](#social-impact-of-dataset)
	- [Discussion of Biases](#discussion-of-biases)
	- [Other Known Limitations](#other-known-limitations)
	- [Additional Information](#additional-information)
	- [Dataset Curators](#dataset-curators)
	- [Licensing Information](#licensing-information)
	- [Citation Information](#citation-information)
	- [Contributions](#contributions)

	## Dataset Description

	- Homepage: https://huggingface.co/datasets/allenai/c4
	- Paper: https://arxiv.org/abs/1910.10683

	### Dataset Summary

	A colossal, cleaned version of Common Crawl's web crawl corpus. Based on Common Crawl dataset: "https://commoncrawl.org".

	This is the version prepared by AllenAI, hosted at this address: https://huggingface.co/datasets/allenai/c4

	It comes in four variants:

	- `en`: 305GB in JSON format
	- `en.noblocklist`: 380GB in JSON format
	- `en.noclean`: 2.3TB in JSON format
	- `realnewslike`: 15GB in JSON format

	The `en.noblocklist` variant is exactly the same as the `en` variant, except we turned off the so-called "badwords filter", which removes all documents that contain words from the lists at https://github.com/LDNOOBW/List-of-Dirty-Naughty-Obscene-and-Otherwise-Bad-Words.

	### Supported Tasks and Leaderboards

	C4 is mainly intended to pretrain language models and word representations.

	### Languages

	The dataset is in English.

	## Dataset Structure

	### Data Instances

	An example form the `en` config is:

	```
	{
	'url': 'https://klyq.com/beginners-bbq-class-taking-place-in-missoula/',
	'text': 'Beginners BBQ Class Taking Place in Missoula!\nDo you want to get better at making delicious BBQ? You will have the opportunity, put this on your calendar now. Thursday, September 22nd join World Class BBQ Champion, Tony Balay from Lonestar Smoke Rangers. He will be teaching a beginner level class for everyone who wants to get better with their culinary skills.\nHe will teach you everything you need to know to compete in a KCBS BBQ competition, including techniques, recipes, timelines, meat selection and trimming, plus smoker and fire information.\nThe cost to be in the class is $35 per person, and for spectators it is free. Included in the cost will be either a t-shirt or apron and you will be tasting samples of each meat that is prepared.',
	'timestamp': '2019-04-25T12:57:54Z'
	}
	```

	### Data Fields

	The data have several fields:

	- `url`: url of the source as a string
	- `text`: text content as a string
	- `timestamp`: timestamp as a string

	### Data Splits

	\| name \| train \|validation\|
	\|----------------\|--------:\|---------:\|
	\| en \|364868892\| 364608\|
	\| en.noblocklist \|393391519\| 393226\|
	\| en.noclean \| ?\| ?\|
	\| realnewslike \| 13799838\| 13863\|

	## Dataset Creation

	### Curation Rationale

	[More Information Needed]

	### Source Data

	#### Initial Data Collection and Normalization

	C4 dataset is a collection of about 750GB of English-language text sourced from the public Common Crawl web scrape. It includes heuristics to extract only natural language (as opposed to boilerplate and other gibberish) in addition to extensive deduplication. You can find the code that has been used to build this dataset in [c4.py](https://github.com/tensorflow/datasets/blob/5952d3d60d60e1727786fa7a9a23d24bb463d4d6/tensorflow_datasets/text/c4.py) by Tensorflow Datasets.

	The dataset was explicitly designed to be English only: any page that was not given a probability of at least 99% of being English by [langdetect](https://github.com/Mimino666/langdetect) was discarded.

	#### Who are the source language producers?

	[More Information Needed]

	### Annotations

	#### Annotation process

	[More Information Needed]

	#### Who are the annotators?

	[More Information Needed]

	### Personal and Sensitive Information

	[More Information Needed]

	## Considerations for Using the Data

	### Social Impact of Dataset

	[More Information Needed]

	### Discussion of Biases

	[More Information Needed]

	### Other Known Limitations

	[More Information Needed]

	## Additional Information

	### Dataset Curators

	[More Information Needed]

	### Licensing Information

	AllenAI are releasing this dataset under the terms of ODC-BY. By using this, you are also bound by the Common Crawl terms of use in respect of the content contained in the dataset.

	### Citation Information

	```
	@article{2019t5,
	author = {Colin Raffel and Noam Shazeer and Adam Roberts and Katherine Lee and Sharan Narang and Michael Matena and Yanqi Zhou and Wei Li and Peter J. Liu},
	title = {Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer},
	journal = {arXiv e-prints},
	year = {2019},
	archivePrefix = {arXiv},
	eprint = {1910.10683},
	}
	```

	### Contributions

	Thanks to [@dirkgr](https://github.com/dirkgr) and [@lhoestq](https://github.com/lhoestq) for adding this dataset.