Zotero WebDav Server

Zotero is a free, easy-to-use tool to help collect, organize, and cite research papers. This is widely used, and really helpful for graduate students / researchers.

What’s nice is Zotero handles syncing of all the articles you collected over the years as well as their attachments (most likely PDFs of the corresponding article) on different machines. The actual metadata of the articles that you saved are stored on the zotero server for free, and to my knowledge, does NOT have a limit. However, there is a limit on the attachment files stored on the Zotero server, i.e. the actual PDFs for the articles. If you’re on the free-plan, the upper limit quota is 300MB. For 2GB storage, you would need \$20 per year, and 6GB for \$60 per year. See pricing here .