The website Sci-Hub enables users to download PDF versions of scholarly articles, including many articles that are paywalled at their journal’s site. Sci-Hub has grown rapidly since its creation in 2011, but the extent of its coverage has been unclear. Here we report that, as of March 2017, Sci-Hub’s database contains 68.9% of the 81.6 million scholarly articles registered with Crossref and 85.1%
![Research: Sci-Hub provides access to nearly all scholarly literature](https://cdn-ak-scissors.b.st-hatena.com/image/square/779875532655fca0276adb45454e05a6c4c26cae/height=288;version=1;width=512/https%3A%2F%2Fiiif.elifesciences.org%2Fjournal-cms%2Farticle%252F2020-07%252Fmetadata-9-red-small.jpg%2Ffull%2F2000%2C%2F0%2Fdefault.jpg)