Cloud Sync

DSM Version

Cloud Sync


  • Safe and secure real-time data synchronization between Synology NAS and multiple public cloud storage services
  • Flexible and customizable options such as sync directions, schedule arrangements, and bandwidth control
  • Centralized management for administrators to monitor and control resource usage


  • Supported cloud storage services include:
    • Synology C2 Object Storage
    • Alibaba Cloud Object Storage Service (OSS)
    • Amazon S3 compatible cloud services
      • Amazon S3
      • hicloud S3
    • Backblaze B2
    • Baidu Cloud
    • Box
    • Dropbox (including Dropbox for Business)
    • Dropbox Team Space (Dropbox Business)
    • Google Cloud Storage
    • Google Drive (including Google Drive for Work)
    • HiDrive
    • JD Cloud
    • Megafon Megadisk
    • Microsoft Azure (Global and China)
    • Microsoft OneDrive (including Microsoft 365 and OneDrive for Business)
    • OpenStack Swift compatible cloud services
      • RackSpace
      • RackSpace UK
    • Tencent Cloud Object Storage (COS)
    • WebDAV
    • Yandex Disk
  • Maximum number of concurrent upload/download files: Between 3 and 20 files
  • Maximum number of records to retain in history: Between 5 and 100,000 entries
  • Supports flexible synchronization options:
    • Bi-directional synchronization
    • One-way synchronization - download remote changes only
    • One-way synchronization - upload local changes only
  • Supports syncing general and encrypted shared folders
  • Supports advanced consistency check by comparing the hash of each file between the public cloud and the Synology NAS to enhance the integrity check of the sync results
  • Supports multiple synchronization connections
  • Supports scheduling sync tasks by choosing the specific time bracket when the task will be running or be suspended
  • Supports configuring polling period to control the next search time for file changes on the public cloud
  • Supports bandwidth control for maximum upload/download rate for a single file
  • Ensures security and reduces storage consumption of uploaded files with client-side AES-256 encryption and compression
  • Maps and syncs single or multiple folders between the public cloud and the Synology NAS in a single connection
  • Offers the option to choose whether to re-fetch or remove files from your public cloud when they're deleted locally
  • Offers administrator mode for centralized user and cloud type management
  • Converts Google Docs to Microsoft Office or jpeg formats in download-only tasks to maintain an offline backup copy
  • Blacklist of file types (music, video, image, document, Google Docs, Box Docs), maximum file size, file name, and file extension for syncing files and folders for each syncing task
  • Provides logs of detailed information of the event, date, and time for each file or folder for each task
  • Offers Windows and Linux decryption tools for data recovery


  • Syncing mounted and external shared folder on the Synology NAS is not supported (EDS14 is excluded)
  • Speed limits are imposed by cloud service providers
  • Upload and download file size limitations are imposed by cloud service providers
  • Files with file name limitation imposed by cloud providers cannot be synced (Refer to this link for more information)
  • No incremental updates. Whenever a file is modified, it must be re-downloaded and synced even if only partial modification was made