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
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
Dataset Card for C4
Table of Contents
- Dataset Card for C4
Dataset Description
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 formaten.noblocklist: 380GB in JSON formaten.noclean: 2.3TB in JSON formatrealnewslike: 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 stringtext: text content as a stringtimestamp: 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 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 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},
}