The crawl archive for September 2016 is now available! The archive located in the commoncrawl bucket at crawl-data/CC-MAIN-2016-40/ contains more than 1.72 billion web pages.
To extend the seed list, we mined sitemaps from the robots.txt dataset and sorted the list of sitemap URLs based on host-level page ranks from Common Search. The highest-ranked 150,000 sitemaps were added to the crawl seed list. For the majority of sitemaps, a maximum of 5,000 potential new URLs per-sitemap were allowed. For the top 5,000 hosts/sitemaps, up to 200,000 potential new URLs were allowed. As a result, the September crawl archive contains 150 million previously unknown URLs. We plan to extend this approach in depth (allowing more URLs per sitemap) and breadth (adding sitemaps from more hosts), provided that it does not impact the quality of crawled content in terms of duplicates and/or spam.
To assist with exploring and using the dataset, we provide gzipped files that list:
- all segments (CC-MAIN-2016-40/segment.paths.gz)
- all WARC files (CC-MAIN-2016-40/warc.paths.gz)
- all WAT files (CC-MAIN-2016-40/wat.paths.gz)
- all WET files (CC-MAIN-2016-40/wet.paths.gz)
By simply adding either s3://commoncrawl/ or https://data.commoncrawl.org/ to each line, you end up with the S3 and HTTP paths respectively.
The Common Crawl URL Index for this crawl is available at: https://index.commoncrawl.org/CC-MAIN-2016-40/.
For more information on working with the URL index, please refer to the previous blog post or the Index Server API. There is also a command-line tool client for common use cases of the URL index.
WARC archives containing containing robots.txt files and responses without content (404s, redirects, etc.) are also provided:
- robots.txt files (CC-MAIN-2016-40/robotstxt.paths.gz)
- non-200 HTTP status code responses (CC-MAIN-2016-40/non200responses.paths.gz)
Please donate to Common Crawl if you appreciate our free datasets! We’re also seeking corporate sponsors to partner with Common Crawl for our non-profit work in open data. Please contact info@commoncrawl.org for sponsorship information and packages.
Erratum:
Charset Detection Bug in WET Records
The charset detection required to properly transform non-UTF-8 HTML pages in WARC files into WET records didn't work before November 2016 due to a bug in IIPC Web Archive Commons (see the related issue in the CC fork of Apache Nutch). There should be significantly fewer errors in all subsequent crawls. Originally discussed here in Google Groups.
Erratum:
Missing Language Classification
Starting with crawl CC-MAIN-2018-39 we added a language classification field (‘content-languages’) to the columnar indexes, WAT files, and WARC metadata for all subsequent crawls. The CLD2 classifier was used, and includes up to three languages per document. We use the ISO-639-3 (three-character) language codes.