Datasets › C4

C4 (Colossal Clean Crawled Corpus)

Introduced by Colin Raffel et al. in Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer23 Oct 2019 archive 2025-07-28

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.

Benchmarks archive 2025-07-28

All 1 leaderboard whose dataset resolves to this page shown (sort by any header). "First row" is the archive's own first row at snapshot, in the archive's row order; nothing here re-ranks and metric direction is not asserted.

First row (archive order)PaperCode
Language Modelling C4 Primer Perplexity 12.35 Primer: Searching for Efficient Transformers for... labmlai/annotated_deep_learning_paper_implementations +3 9 Compare

Papers archive 2025-07-28

3 shown of 3 papers with a leaderboard row on this dataset's benchmarks, newest first. The archive's own "papers using this dataset" list was never published, so this is the benchmark-backed subset; the archive's count for this dataset is 981. The Syntology column is from Syntology's graph (read 2026-09-24), stated per sample; it is not part of any archive number.

DateSamples run Syntology
LLM.int8(): 8-bit Matrix Multiplication for Transformers at Scale 4 4 15 Aug 2022 ran 2 of 5 samples (3 unverified)
N-Grammer: Augmenting Transformers with latent n-grams 2 2 13 Jul 2022 ran 0 of 6 samples (6 unverified)
Primer: Searching for Efficient Transformers for Language Modeling 4 3 17 Sep 2021 ran 3 of 3 samples (0 unverified; 3 pointer-only for licence)

Dataset loaders archive 2025-07-28

7 loaders as listed in the archive; links are outbound and not re-checked here.

Tasks archive 2025-07-28

License archive 2025-07-28

Unknown

Modalities archive 2025-07-28

Languages archive 2025-07-28

Variants archive 2025-07-28

  • C4
  • c4 en

2 variant names, as the archive lists them.

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