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March 14, 2021

February/March 2021 crawl archive now available

The crawl archive for February/March 2021 is now available! The data was crawled between February 24th and March 9th and contains 2.7 billion web pages or 280 TiB of uncompressed content. It includes page captures of 1.2 billion new URLs, not visited in any of our prior crawls.

The crawl archive for February/March 2021 is now available! The data was crawled between February 24th and March 9th and contains 2.7 billion web pages or 280 TiB of uncompressed content. It includes page captures of 1.2 billion new URLs, not visited in any of our prior crawls.

Data Type File List #Files Total Size
Compressed (TiB)
Segments segment.paths.gz 100
WARC warc.paths.gz 64000 62.51
WAT wat.paths.gz 64000 18.44
WET wet.paths.gz 64000 8.06
Robots.txt files robotstxt.paths.gz 64000 0.20
Non-200 responses non200responses.paths.gz 64000 1.58
URL index files cc-index.paths.gz 302 0.21
Columnar URL index files cc-index-table.paths.gz 900 0.23

Improvements and Fixes

The ISO639-3 code for the Hmong language was updated to "hmn" - the code "blu" used so far was already deprecated in 2008. Crawl archives prior to this crawl will still use the code "blu". More details about this update are found here.

Archive Location and Download

The February/March crawl archive is located in the commoncrawl bucket at crawl-data/CC-MAIN-2021-10/.

To assist with exploring and using the dataset, we provide gzipped files which list all segments, WARC, WAT and WET files.

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-2021-10/. Also the columnar index has been updated to contain this crawl.

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.

This release was authored by:
No items found.

Erratum: 

WARC Content-Type header in revisit records

Originally reported by: 
Sebastian Nagel
More details
Common Crawl's WARC revisit records use Content-Type: message/http (following the WARC 1.1 spec's example), but per iipc/warc-specifications#55 it should be application/http;msgtype=response for consistency with other HTTP response records.

Erratum: 

Redirect target URL in URL indexes may be a relative URL

Originally reported by: 
Sebastian Nagel
More details
When the HTTP “Location” header includes a relative URL, the corresponding “redirect” field in the CDX index and “fetch_redirect” field in the columnar index will also store a relative URL. In all other cases, redirect targets in the URL indexes should be recorded as absolute URLs.

Erratum: 

Content is truncated

Originally reported by: 
More details
Some archived content is truncated due to fetch size limits imposed during crawling. This is necessary to handle infinite or exceptionally large data streams (e.g., radio streams). Prior to March 2025 (CC-MAIN-2025-13), the truncation threshold was 1 MiB. From the March 2025 crawl onwards, this limit has been increased to 5 MiB.

Erratum: 

SURT URLs do not properly encode non-UTF-8 percent-encoded characters

Originally reported by: 
Tom Morris
More details
When constructing SURT (Sort-friendly URI Reordering Transform) URLs, percent-encoded characters that are not valid UTF-8 sequences were not being correctly handled. This could lead to inconsistencies in URL normalization and sorting, potentially causing incorrect deduplication or retrieval issues in datasets that rely on SURT-based indexing.

Erratum: 

WAT data: repeated WARC and HTTP headers are not preserved

Originally reported by: 
More details
Repeated HTTP and WARC headers were not represented in the JSON data in WAT files.

Erratum: 

WARC revisit metadata records

Originally reported by: 
More details
The revisit records in the Common Crawl WARC archives (since Aug 2018) lack the metadata record which is attached to all response records.

Erratum: 

Erroneous title field in WAT records

Originally reported by: 
Robert Waksmunski
More details
The title field in WAT record is extracted from last but not first <title> element in an HTML page