--- task_categories: - text-generation pretty_name: Common Crawl Host Index v2 size_categories: - 10B>> from datasets import load_dataset >>> ds = load_dataset("commoncrawl/host-index-testing-v2", data_dir="data/crawl=CC-MAIN-2025-18", split="train", streaming=True) Resolving data files: 100%|████████████| 30/30 [00:00<00:00, 43614.95it/s] >>> print(next(iter(ds))) {'nutch_unfetched_pct': 0, 'fetch_other': 0, 'fetch_200_lote': 0, 'nutch_gone': 3, 'nutch_gone_pct': 7, 'robots_gone': 0, 'robots_5xx': 0, 'hcrank10': 3.446, 'warc_record_length_median': 32867, 'hcrank': 11908759.0, 'nutch_fetched': 42, 'nutch_notModified_pct': 0, 'robots_4xx': 0, 'nutch_redirTemp': 0, 'fetch_redirPerm': 2, 'fetch_4xx': 0, 'url_host_tld': 'ae', 'nutch_fetched_pct': 93, 'robots_notModified': 0, 'robots_other': 0, 'nutch_redirTemp_pct': 0, 'fetch_200_lote_pct': 0, 'nutch_numRecords': 45, 'robots_3xx': 0, 'robots_redirTemp': 0, 'warc_record_length_av': 31769, 'url_host_registered_domain': 'ebury.ae', 'surt_host_name': 'ae,ebury', 'nutch_redirPerm_pct': 0, 'fetch_redirTemp': 0, 'robots_200': 3, 'fetch_3xx': 0, 'fetch_5xx': 0, 'nutch_unfetched': 0, 'prank': 4.73550733982247e-09, 'fetch_gone': 0, 'prank10': 0.0, 'robots_redirPerm': 1, 'fetch_notModified': 0, 'nutch_redirPerm': 0, 'fetch_200': 18, 'nutch_notModified': 0} ``` ## Use Cases ### Example questions this index can answer - What's our history of crawling a particular website, or group of websites? - What popular websites have a lot of non-English content? - What popular websites seem to have so little content that we might need to execute javascript to crawl them? ### Example questions that we'll use to improve our crawl - What's the full list of websites where more than half of the webpages are primarily not English? - What popular websites end our crawls with most of their crawl budget left uncrawled? ### Example questions that future versions of this host index can answer - What websites have a lot of content in particular languages? - What websites have a lot of content with particular Unicode scripts? ## Examples US Federal government websites in the *.gov domain (about 1,400 domains, y-axis scale is millions): ![current-federal.txt_sum.png](https://commoncrawl.github.io/cc-host-index-media/current-federal.txt_sum.png) [See all graphs from this dataset](https://commoncrawl.github.io/cc-host-index-media/current-federal.txt.html) commoncrawl.org fetch. You can see that we revamped our website in CC-2023-14, which caused a lot of permanent redirects to be crawled in the next few crawls: ![commoncrawl.org_fetch.png](https://commoncrawl.github.io/cc-host-index-media/commoncrawl.org_fetch.png) [See all graphs from this dataset](https://commoncrawl.github.io/cc-host-index-media/commoncrawl.org.html) ### Python code examples More examples of how to use this dataset with Python can be found at the [Common Crawl Host Index GitHub repo](https://github.com/commoncrawl/cc-host-index). ## Highlights of the Schema - There is a Hive-style partition on `crawl`, which is a crawl name like `CC-MAIN-2025-13`. - There is one row for every webhost in the web graph, even if we didn't crawl that website in that particular crawl - The primary key is `surt_host_name`, which stores the URL in [Sort-friendly URI Reordering Transform (SURT) format](http://crawler.archive.org/articles/user_manual/glossary.html#surt). For example, the URI `commoncrawl.org` -> becomes `org,commoncrawl)`. - There is also `url_host_tld`, which we recommend that you use whenever possible (eg `org` for commoncrawl.org) - it typically improves performance, significantly. - There are counts of what we stored in our archive (`warc`, `crawldiagnostics`, `robots`) - `fetch_200, fetch_3xx, fetch_4xx, fetch_5xx, fetch_gone, fetch_notModified, fetch_other, fetch_redirPerm, fetch_redirTemp` - `robots_200, robots_3xx, robots_4xx, robots_5xx, robots_gone, robots_notModified, robots_other, robots_redirPerm, robots_redirTemp` - There is ranking information from the [web graph](https://commoncrawl.org/web-graphs): harmonic centrality, page rank, and both normalized to a 0-10 scale - `hcrank`, `prank`, `hcrank10`, `prank10` - There is a language summary (for now, just the count of languages other than English (LOTE)) - `fetch_200_lote, fetch_200_lote_pct` - For a subset of the numbers, there is a `foo_pct` (eg `fetch3xx_pct`) which can help you avoid doing math in SQL. It is an integer 0-100. - There are raw numbers from our crawler logs, which also reveal the crawl budget and if we exhausted it - `nutch_fetched, nutch_gone, nutch_notModified, nutch_numRecords, nutch_redirPerm, nutch_redirTemp, nutch_unfetched` - `nutch_fetched_pct, nutch_gone_pct, nutch_notModified_pct, nutch_redirPerm_pct, nutch_redirTemp_pct, nutch_unfetched_pct` - There is a size summary (average and median size (compressed)) - `warc_record_length_median, warc_record_length_av` (will be renamed to _avg in v3) The full schema is available here: [athena_schema.v2.sql](https://github.com/commoncrawl/cc-host-index). ## Known bugs - Some of the partitions have a different schema from others, so you will get errors for some of the columns in some of the crawls. We recommend that you avoid using those crawls, and only use the columns you need. - When the S3 bucket is under heavy use, AWS Athena will sometimes throw 503 errors. We have yet to figure out how to increase the retry limit. - Hint: https://status.commoncrawl.org/ has graphs of S3 performance for the last day, week, and month. - The sort order is a bit messed up, so database queries take more time than they should. ## Expected changes in test v3 - `warc_record_length_av` will be renamed to `_avg` (that was a typo) - more `_pct` columns - count truncations: length, time, disconnect, unspecified - addition of indegree and outdegree from the web graph - improve language details to be more than only LOTE and LOTE\_pct - `content_language_top`, `content_language_top_pct` - add unicode block information, similar to languages - `prank10` needs its power law touched up (`hcrank10` might change too) - there's a sort problem that .com shards have a smattering of not-.com hosts. This hurts performance. - add domain prank/hcrank - CI running against S3 - `robots_digest_count_distinct` - `robots_digest` (if there is exactly 1 robots digest) - Summarize `fetch_redirect`: same surt, same surt host, other. ## Contributing We'd love to get testing and code contributions! Here are some clues: - We'd love to hear if you tried it out, and what your comments are - We'd love to have python examples using Athena, similar to duckdb - We'd love to have more python examples - Please use pyarrow whenever possible ## Terms of Use [https://commoncrawl.org/terms-of-use](https://commoncrawl.org/terms-of-use)