General limits when using Sync

In this article:

How many files can I store in my Sync account?

The number of files you can store with Sync is limited by the amount of storage space in your Sync account. If you run out of space in your Sync account, you can upgrade to get more space.

You can store as many files as your storage space allows, however, you may not be able to synchronize all of your files to all of your computers, as the number of files you can sync is also limited by the size of your computer's available hard drive space. If you do not have enough space on your computer, try using selective sync, Vault, or consider moving your Sync files to a larger, external USB hard drive.

The Sync desktop app and web panel: Sync performance can get slower with more than 300,000 files in Sync. This is not a hard limit, and depends on the hardware specifications of the computer running the app (or web browser), as well as network speed, nested folder structure, and frequency of syncing activity. Many customers successfully sync more files without issue.

Also to note, there is a hard limit of 50,000 files per folder (you can create an unlimited number of folders).

The Sync mobile app: The Sync apps for iOS and Android provide a file listing, but do not physically store file data on your phone or device by default. This ensures that the number of files you can store with Sync is not limited by the amount of available storage space on your device.

The mobile apps include a feature called sync offline, which allows you to selectively store file data on your phone or device. Offline folders support up to 10,000 files per folder and/or up to 100 GB of data per folder. The total of all offline files and folders synced to a mobile device cannot exceed 100,000 files and/or 500 GB.

How many computers or devices can I connect to my Sync account?

You can connect up to 5 active computers or mobile devices to your Sync account.

If you’re setting up Sync for multiple people, each person must use their own Sync account (don’t share one login across multiple users). Sharing a single account can cause:

  • Security and privacy issues: if everyone has the same access, actions can’t be tied to an individual user.

  • Device and access management problems: it’s harder to track devices, remove access, and stay in control.

  • Confusing sync behavior: multiple people working under one login can cause unexpected changes and file conflicts.

Instead, create a separate Sync account for each user, then use team shared folders to control who can access which folders and files.

Can I upload large files to Sync (what is the maximum file size)?

Sync.com desktop and mobile apps: You can transfer files of any size using the Sync desktop or mobile apps, however, Sync desktop app performance may be slower when transferring individual files larger than 40 GB. This is not a hard limit, and depends on the hardware specifications of the computer running the app, as well as the frequency of changes to the file. Many customers successfully transfer much larger files without issue.

Sync.com web panel: For large file transfers, we recommend using the Sync desktop app, which supports automatic resume on partial transfers and does not otherwise restrict file size. Because the Sync web panel is browser-based, web panel performance can degrade when transferring individual files larger than 500 MB in size.

Does Sync support file de-duplication or block level syncing?

The Sync desktop and mobile apps support file-level de-duplication, which means that if an identical file already exists in your account, Sync will recognize it and avoid uploading the file again, even if it has been renamed or moved. This helps reduce bandwidth usage, speeds up sync times, and avoids unnecessary data duplication.

For example, if you copy a large video file to another folder within your Sync folder, the desktop app won’t re-upload the entire file. Instead, it will create a new reference to the existing copy already stored in your account.

However, Sync does not support block-level de-duplication, which involves analyzing portions of a file (blocks or chunks) to detect partial matches. While this technique can optimize syncing even further, it would require Sync to scan and access the content of your files. To maintain zero-knowledge privacy, we deliberately avoid this method and cannot access or inspect your files.

What types of files are supported?

You can upload virtually any type of file to Sync, including documents, videos, photos, compressed archives, RAW files, image files and more. Furthermore, Sync does not alter or compress your files in any way.

Sync should not be used to synchronize live databases or live application data across multiple computers, although you can use Vault to periodically backup this type of data.

Important note: To prevent syncing problems across different operating systems and platforms, a subset of incompatible characters are not supported by Sync. Files named with these characters may be skipped (not uploaded), and will be listed under the desktop app progress tab (regardless of syncing status).

What are the data transfer limits (bandwidth / traffic)?

Sync does not limit the amount of data you can upload or download, provided that you have not exceeded the total storage space in your account. You can increase your space by upgrading your account. You can also delete files from your account to free up space, to transfer more data.

Sharing: Sync Pro customers can transfer unlimited data and unlimited downloads when sharing. This means that there are no monthly transfer limits when sharing files, provided you are on a Pro plan. The free Sync Starter plan allows up to 20 downloads per day, per link. The limit resets every 24 hour period. You can upgrade to a Pro plan any time to get unlimited downloads immediately.

What is the maximum transfer speed?

Real world transfer speeds will vary, depending on the speed of your own Internet connection, network peering between your ISP and our upstream provider, the amount of data you are transferring, and the size of the files being transferred.

At 40 Mbps (40 megabits per second, or 5 megabytes per second), a 1 GB (1,000 MB) file should take less than 5 minutes to transfer. This estimate does not include encryption overhead, which is typically not noticeable on small files, but can add additional time when transferring very large files.

How many team shared folders can I create?

Sync Pro and Business customers can create unlimited Team Shared Folders. Free Sync Starter customers can create up to three Team Shared Folders.

Recommended setup for best performance:

While paid plans support an unlimited number of Team Shared Folders, the recommendations below help keep large deployments fast and easy to manage:

  • Keep your total number of active shares under 200 (recommended).

  • For sharing with 50+ people, use links when possible. Shared links typically provide the best performance and can be accessed by an unlimited number of recipients.

  • For large organizations, segment your folder structure. Create separate Team Shared Folders by department or project, and use groups to manage access across multiple folders instead of relying on a single, large share.

Note: People you share with may be limited by the amount of space available on their own computers or devices.

Sync Pro and Business customers can create unlimited links, with unlimited data transfer. Free Sync Starter customers can create up to three (3) links with limited data transfer.

When sharing folders with links, the people you share with may have an option to download all files in the folder at once. See here for download as Zip best practices and limitations.

Consider using team shared folders to share folders and files larger than 20 GB in size, or when sharing thousands of files.

Note: The people you share with may be limited by the amount of space available on their own computers or devices.

Can I use network drives, SD cards, mapped drives or network attached storage (NAS) with Sync?

You cannot use network drives, SD cards, mapped drives or network attached storage as your Sync folder location. Also, Sync does not support third-party transfer protocols such as WebDAV or FTP.

What are the minimum system requirements?

Desktop: 

Windows 8, 10 and 11 (10+ for CloudFiles)

  • You’ll need admin privileges on your computer to install and run Sync.
  • You can install Sync on an NTFS formatted internal or USB attached external drive.
  • Sync does not support exFAT or network drives.

macOS 10.11 and greater (13+ for CloudFiles)

  • You’ll need admin privileges on your computer to install and run Sync.
  • Sync for Mac does not support external or network drives.

Mobile:

  • iOS (iPhones and iPads)
  • Android phones and tablets

Web:

On desktop computers and mobile devices, the web panel is compatible with:

  • Chrome and Edge v114+
  • Safari (MacOS & iOS) v14+
  • Firefox v90+

You’ll need admin privileges on your computer to install and run Sync.

Sync does not support Windows Server operating systems or running as a service.

Can I install Sync on Linux?

A Linux app is on our long-term roadmap, however, not available at this time. In the mean time you can access the Sync.com web panel on Linux using a supported web browser.

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