How to Increase Your Zotero Cloud Storage: 4 Ways

The Zotero “personal research assistant” comes with 300 MB of cloud storage free for attachments in each account.1 That’s a good amount, but it can go quickly, especially if you start storing larger PDFs in your Zotero library.

For instance, the Bavarian State Library has made available PDF scans of Gabriel Vasquez’s entire 4-volume Commentariorum ac disputationum in primam partem Sancti Tomæ. But if you download volume 4, the smallest, and want to store it in your Zotero library, you’ll need 372 MB of storage space.

So, what happens when you use all your Zotero cloud storage but still want to synchronize attachments between multiple computers or just back them up to the cloud?

Two options will require some new cloud storage or new configuration to your existing cloud storage. But another two will let you use the cloud storage you already have as is.

1. Subscribe to a paid Zotero storage plan.

For users who require additional cloud storage, Zotero offers three paid plans, ranging from 2 GB for $20 per year to unlimited for $120 per year.2 Zotero also offers special storage plans for laboratory and institution-wide deployments.3

This option is the most straightforward. It makes it easier for you to access your stored attachments via mobile applications the Zotero app that’s in beta for iOS.4 The downside is that this solution requires paying for an additional cloud storage service.

2. Use your own WebDAV service.

In addition to synchronizing attachment files to Zotero storage, Zotero also supports the WebDAV protocol.5 WebDAV stands for “Web Distributed Authoring and Versioning” and is

an extension to Hypertext Transfer Protocol (HTTP) that defines how basic file functions such as copy, move, delete, and create are performed by using HTTP.6

2.1. Normal WebDAV

If you want to explore this route you can explore setting up your own self-hosted WebDAV service. Or you can look into the Zotero documentation’s list of providers whose WebDAV service is known to work with Zotero.7

Each provider makes available 2–15 GB of free storage. But some also have lower limitations for individual attachment file sizes. In addition, as you’ll see from the notes on several services, you might encounter bugs, problems, or important limitations in trying to use these ready-made WebDAV options.

So, synchronizing attachments via an alternative WebDAV service may be more economical than doing so via Zotero storage. But it will still require some special configuration and perhaps also mean you’ll need to use additional cloud storage service.

2.2. Koofr WebDAV

If you don’t have WebDAV-accessible storage already and aren’t keen on setting up your own WebDAV server, you do have the option of trying a service like Koofr.

Based in Slovenia, Koofr is subject to the European Union’s regulations about data privacy and security.8 Koofr supports application programming interface (API) connections with storage providers wherever the providers have them.

This is the kind of authentication where you don’t give Koofr any login details for your storage provider, as you shouldn’t. Instead, when you create the connection, you’ll see a popup from your storage provider itself asking if you want to authorize a connection to Koofr.9

You can secure even a free Koofr account with multi-factor authentication (MFA).10 And a free Koofr account will allow you to configure WebDAV access to a specific folder in a cloud storage account like OneDrive.11

Once set up, you should be able to connect to this folder from the Zotero mobile apps by entering the username and password you configured in Koofr.

Personally, I haven’t had great luck with this option. In theory, it should work. But for me, WebDAV will typically fail to connect, or it will connect but my full library won’t synchronize.

This said, using Koofr for WebDAV may work better with other storage providers like Dropbox or Google Drive. Or it may work better with smaller libraries.

So, if you try this option successfully, please comment below on how you set it up and how well you find it to work.

A Sidebar on What to Synchronize and What Not to Synchronize in Generic Cloud Storage

There are, however, two other ways you can use Zotero to store attachments in cloud storage that you already have. When doing so, it’s important to note that you should not allow a generic cloud storage service like Dropbox, Google Drive, or OneDrive to touch your Zotero database.

Configured correctly, you can safely have some such providers to synchronize the rest of your Zotero profile. But if you try to synchronize your Zotero database with a cloud service, you’re setting yourself up for any number of headaches and may well lose data or corrupt your database file.12 (I’ve made this mistake before. It’s not pretty.)

So, when you synchronize your Zotero database, you should always use your Zotero account and Zotero’s servers. There’s no downside to this as there’s no limit to how many records you can have in your Zotero database. The only thing that counts against a storage limit are files you might want to attach to those records (e.g., PDFs, webpage snapshots).

3. Move your Zotero storage folder.

By default, Zotero stores attachment files in its storage folder. To find your storage folder, with Zotero open, go to Edit > Advanced > Files and Folders. From the “Files and Folders” tab of the Zotero Preferences dialog box, you can change the directory where Zotero saves all its files, including its main database.

Don’t do this. All you want here is the location of your Zotero profile folder. Once you’ve found this, you can change the storage folder’s location by using a “symbolic link” (or “symlink”).

A symlink isn’t the same as a “shortcut.” A shortcut simply bounces you from one location to another in your file system.

Instead, a symlink allows access to a file or folder via two different paths. So, it’s a bit like using two different email addresses to get messages into the same inbox.

For instance, if you’re on Windows, you can use a symlink to change the location of your Zotero storage directory by taking the following steps.

3.1. Open your Zotero directory.

By default in Windows 10, Zotero saves all its files under C:\Users\{username}\Zotero. Before proceeding to the other steps, you may want to back up this directory to a safe place, just in case something goes amiss.

3.2. Move the “storage” folder.

Inside the Zotero directory, you should find a folder named “storage.” Make sure Zotero is closed, and move this folder to the cloud storage folder of your choice. You can also rename the folder if you’d like for ease of reference.

So, for instance, I’ve created a directory D:\OneDrive\Research\Zotero. This directory contains all the sub-folders and files Zotero looks for in “storage.”

3.3. Create the symlink to your new Zotero storage location.

To create the symbolic link:

  1. Open the Windows menu.
  2. Search for “cmd” or “Command Prompt.”
  3. Right-click this program, and choose “Run as administrator.”
  4. If you are asked whether you want to allow this app to make changes to your device, choose “Yes.”
  5. Enter cd C:\Users\{username}\Zotero. You’ll need to replace {username} with your username as it appears in the file path under step (a) above.
  6. Type mklink /d "storage" {file path where you moved the Zotero "storage" folder}. You’ll need to replace {file path where you moved the Zotero "storage" folder} with the actual file path. This would be D:\OneDrive\Research\Zotero in my example above.
  7. Press Enter.

You should now be able to go back to C:\Users\{username}\Zotero (or wherever your main Zotero folder is) and find there a symbolic link named “storage.” The icon might look like a normal shortcut. But if you click the symbolic, you won’t go to another file path. Instead, Explorer will show the contents of the target folder as if they were contents of the folder where you have your “storage” symlink.

The folder will be located in the cloud storage folder where you’ve moved it. But Zotero will be able to access the folder’s contents in the location it expects for the storage folder.

Next, reopen Zotero, and test opening a few attachments. If they open properly, everything went well. If the attachments don’t open, delete the “storage” symbolic link, and try creating it again via the steps indicated here.

Instead of moving Zotero’s storage folder, you can simply create a folder in a cloud storage service of your choice and have Zotero link to files found there.

4.1. Setup

To do so,

  1. Create the new folder where you want to store Zotero attachments.
  2. Open Zotero, and go to Edit > Preferences > Advanced > Files and Folders.
  3. In the section for Linked Attachment Base Directory, choose the directory you created in your cloud storage folder for housing your attachments. On other computers, you’ll then just need to find the equivalent directory once, tell Zotero where it is, and Zotero will be able to use this base directory without missing a beat.
  4. Click OK.

You’ll then just store in this directory any file you want to link to in Zotero. Go to Zotero, and add choose to Add Link to File… with the appropriate item.

4.2. Zotfile

To make things still a bit easier, if you’re running Zotero 6, you might consider installing the Zotfile extension.

Among other things, Zotfile can make it easier to rename attachments as you save them in your chosen directory or even to move files stored in Zotero’s storage folder into a different attachment directory.

Zotfile has a number of helpful features built-in. But all Zotero 6 extensions will need to be rewritten before they become compatible with Zotero 7. This scenario creates a special concern for Zotfile users, however, because the extension “is currently not actively developed and maintained.”13 So, Zotero 7 support coming to Zotfile at this time seems unlikely.14

It’s possible that some of Zotfile’s functionality may get wrapped into Zotero proper.15 Or a new extension may rise in Zotfile’s place.16

But for the present, it may be best to avoid building a workflow on top of any of Zotfile’s distinctive features. That said, if you find that you really do need to use Zotfile for sending attachments to a specific directory or other purposes, you can always continue running Zotero 6 alongside Zotero 7.

Storing with or without Stores

Whether you use a paid or free option, these steps should give you some additional options to manage your Zotero storage. And as you continue using Zotero, you’re likely to find that this extra space proves extremely helpful for saving your research and avoiding the need to re-search for what you’ve previously found.17

  1. Zotero, “Zotero Storage,” n.d. Header image provided by Oscar Chevillard

  2. Zotero, “Storage.” 

  3. Zotero, “Zotero Lab and Zotero Institution,” n.d. 

  4. Zotero, “‎Zotero,” App Store, n.d. 

  5. Zotero, “Sync,” 20 January 2022. 

  6. Microsoft, “WebDAV,” 19 August 2020. 

  7. Zotero, “List of WebDAV Services,” 14 October 2020. 

  8. “About,” Koofr, n.d. 

  9. “Improving Your Koofr Account Security—Together,” Koofr Blog, n.d.; see also “How Can You Help Keep Your Koofr Account Safe and Secure?,” Koofr Blog, n.d. 

  10. “Account Security.” 

  11. “How Can I Connect OneDrive to Koofr?,” Koofr, n.d.; “Koofr WebDAV Help,” Koofr, n.d. 

  12. Zotero, “Sync.” 

  13. “ZotFile: Advanced PDF Management for Zotero,” Zotfile, n.d. 

  14. “Zotero 7 Support,” GitHub, n.d. 

  15. “On Zotfile Development and Zotero 7,” Zotero Forums, 2023. 

  16. “Zotero 7 Support.” 

  17. Zotero, “Winning Tagline: Research, Not Re-Search,” weblog, Zotero Blog, 26 November 2007. 

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6 responses to “How to Increase Your Zotero Cloud Storage: 4 Ways”

  1. Ruby Avatar

    Hi David! Thank you so much for this information! I tried option number 3 and now I already have the symbolic link “storage” on my PC and although my storage on Zotero cloud is “full” I can add more and more books without problems! It’s amazing! Thanks!!

    1. J. David Stark Avatar

      So glad you found it helpful! 🙂

  2. Jesus Lopez Avatar
    Jesus Lopez

    Hi! Thanks for the detailed writeup, symbolic linking the storage dir is hell of a hot idea, just what I needed.

    1. J. David Stark Avatar

      Glad to hear you found the idea helpful!

  3. Keshav Thapa Avatar
    Keshav Thapa

    Hello David,

    Thanks a lot for your article. I am trying to follow for step 3 however, I am not able to use mlink ( iam in mac). It says that mlink not found in the terminal. Any idea? Thanks a lot!

  4. J. David Stark Avatar

    That’s a good question. I wish I had a Mac that I could use to test. But I think this article should point you in the right direction.

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