Zotero with 15GB free file storage?

I have been using Zotero as my bibliography management software  since 2013 (migrating from EndNote) and have generally been happy with it (and I blogged about it before). Although our university provides EndNote access, most students will lose “free” access after leaving the university. A yearly subscription to EndNote used to set you back about €100 (in Finland via a reseller), which is an unnecessary expense in a student’s budget. EndNote’s “one-time purchase” model is, imho, deceptive marketing, because you are not eligible to major upgrades, which are released approximately yearly. The “upgrade fee” is usually about the same as the yearly subscription used to be.

Zotero + Google Docs for collaborative online editing However, the free Zotero has its limits. Together with four other researchers, I wrote an extensive review article about the secondary vascular system (SVS) in fish  , which was published in 2024. We worked on this review for about two years. With 49 pages and well over 250 references, it is comprehensive. Since the contributors to this manuscript were scattered across Europe (Finland, the Czech Republic, Sweden, and Germany), we needed a real-time collaborative writing environment. We chose Google Docs because a) it is free and b) it supports Zotero. While EndNote supports Online Word 365 for collaborative editing, our IT department has never been able to make it work in our corporate Office 365 environment. They tried, but it never worked for anybody at Helsinki University (correct me if I am wrong and you got it working!). And since Zotero doesn’t support Online Word 365 and EndNote didn’t support Google Docs back in 2022, the Zotero + Google Docs combo was the only viable option. Starting from 2023, EndNote also supports Google Docs, but I do not know how well it performs with 300 or more references. Please let me know if you have tried it out!

Zotero is faster than it used to be In 2023, Zotero started to slow down as the number of our references increased beyond 200. At the very end of the revision process, each reference change took about 1-2 minutes to execute. For larger changes (refreshing or unlinking the bibliography), it took maybe 5 minutes (on Lenovo X390 Yoga, Ubuntu 20.04, Rocket Lake with 16 GB of RAM). Last week, I just completed the revision for another large review on angiogenic doping (370 references, submitted to Sports Medicine  ), and I am happy to report that Zotero has improved. I do not know what they did to speed things up in Zotero 9, but even with 370 references, refreshing or unlinking was about 5x faster than it was two years ago (on the same computer, just updated to Ubuntu 24.04). At one point, Zotero notified me that my library was too large to handle efficiently, but I managed quite well despite the warning.

300 MB limit for group libraries, while WebDAV storage/syncing is limited to “My Library” Zotero is a solid piece of reference manager, but the 300 MB limit for group libraries is a bit on the low side, even for students who don’t have 5000 PDF files attached to their bibliographic entries. My average PDF publication is about 2MB, which means I am limited to about 150 publications in a group library on the free tier. When storing full-text PDFs in my own library (i.e. items under “My Library”), I use my own WebDAV server to synchronize them. There are also free WebDAV servers with 5 GB free storage, but many NAS devices also support WebDAV services, meaning you can easily store and sync many gigabytes of PDF files between computers as long as you keep them in “My Library”.

How-to: Unlimited storage for your group libraries using GDrive But what about group libraries? They only make sense if full-text is also synced, since it is increasingly challenging to hunt down a PDF. Both very old and very new publications are especially tricky. You can alway buy them, but the prices for single articles are ridiculous, often in the rang of $50 or more. So once you have such a valuable file, you want to share it with your co-authors. And that does not work if you have hit the 300 MB limit. Another gotcha is that you’ll easily forget to transfer PDFs when you change to a new computer. PDFs that you attach to a group library are available to you even if they do not sync anymore with the other group members due to 300 MB limit. But it’s easy to forget about them because you might think that item in the group library will sync back to your new computer. That is indeed the case, but it does not include the fulltext. How to deal with such issues? The trick is not to save the PDFs as attached Files, but as attached Web Links, which you store on GDrive (or any other free file storage solution that lets you share your documents freely). How?

Create a folder on your Google Drive, where you place the PDF that you want to link to your Zotero group library Then share the whole folder freely with the world. Right-click the file > Share (or Ctrl-Alt-A) > “General Access” > Change from restricted to “Anyone with the link”. Then copy that link and head over to Zotero, right-click the entry and select “Add Attachment” > “Web Link” and paste the link you just copied from Google Drive. If you store your full-text files on a server that supports HTTP Basic Authentication (most NAS servers do), you can also password-protect your PDF files and include the login/password in the URL that you provide to Zotero (e.g., https://username:password@example.com/protected-zotero-folder/secret.pdf). However, the unguessable URL from GDrive also provides some privacy protection. However, neither protection method is very strong.

Now your Google Drive stores the file while Zotero keeps only the “metadata”, including the information on where in your Google Drive the file is stored. An additional benefit is that syncing is much faster within groups, because no large files need to be transferred.

Link to my public Zotero library: https://www.zotero.org/groups/1329486/the_jeltsch_laboratory/items