Online backup is a special kind of online storage service; however, various products that are designed for file storage may not have features or characteristics that others designed for backup have. Online Backup usually requires a backup client program. A browser-only online storage service is usually not considered a valid online backup service.
Online folder sync services can be used for backup purposes. However, some Online Folder Sync services may not provide a safe Online Backup. If a file is accidentally locally corrupted or deleted, it depends on the versioning features of a Folder Sync service, whether this file will still be retrievable.
Partial, Amazon AWS or Google Cloud Storage[34][87]
Legend
^1Windows/Linux/Mac/iOS/Android/BlackBerry: Supported operating systems for thick client (native binary application), which provide background data transmission and setting services.
^2Zero knowledge: The service provider has no knowledge of the user's encryption key, ensuring privacy of the backup data.[88][89][90]
^3Secure Key Management: If yes, the user holds and controls the encryption key. If no, the service provider holds and controls the encryption key.
Limited MB plan: Pay per computer. Additional fee for storage over a threshold.
Unlimited MB plan: Pay per computer. Storage per computer is unlimited.
$/MB plan: Pay per unit of storage, but unlimited computers may share that storage.
^5Cloud hosted Net Drive: Cloud can serve storage over WebDAV, SMB/CIFS, NFS, AFP or other NAS protocol, allowing files to be streamed from the cloud. A change made to the cloud is immediately accessible to applications on all clients without needing to pre-download (sync) the file in full.
^7Sync: Synchronization between computers, and/or mobile devices (PDA, MDA,...)
^12 Whether the desktop client (if available) can detect and upload changes without scanning all files.
^13 Many backup services offer a limited free plan, often for personal use. Often it is possible to increase the free backup limit through coupons, referrals, or other means that are not included in this column. This column also does not include free trials that are only available for a limited period of time.
^14External hard drive support: Can refer to an alternate backup destination or whether the service can back up external drives.
^15 Hybrid Online Backup works by storing data to local disk so that the backup can be captured at high speed, and then either the backup software or a D2D2C (Disk to Disk to Cloud) appliance encrypts and transmits data to a service provider. Recent backups are retained locally, to speed data recovery operations.
^16Unlimited BW: If bandwidth capping or limits are used on accounts.
Comments
Acronis
Up to five PCs, always incremental backups, remote access from the web
Backblaze
Data de-duplication; block-level incremental.
Barracuda Backup Service
Data de-duplication; real-time hybrid on-site/off-site data back-up.
BullGuard Backup
5 PC/license, fast upload speeds, mobile access, encrypted transfer and storage, password-protected settings, free 24/7 support.
Carbonite
Block-level incremental, Home or Pro editions. iPhone/ Blackberry/ Android App available to remotely access data from the online backup (For Pro: Users of the computer which are backed up, not available for the Administrator of the Pro). Can manually select files to upload that are larger than 4 GB.
Cloudberry Backup
Image & File Based backups, data de-duplication, block-level and multiple cloud providers supported.
CloudJuncxion
Decentralized multi-cloud backup with integrated sharing, sync, backup, and Cloud NAS. Fault-tolerance against failure of a constituent cloud.
Crashplan
Unlimited destinations. Data de-duplication; block-level incremental. Can run server-free, exchanging backup space with friends and family.
Cloud storage that is specifically designed for the Mac. Also allows users to store files exclusively in the cloud for seamless access on any computer or mobile device.
Diino
iPhone/Android app available.
Dropbox
Data de-duplication, delta sync, iPhone/Android/Blackberry app available.
Dropmysite
website backup, database backup, SFTP support, free up to 2 GB.
Egnyte
Delta sync, Google Docs sync, user and group management
ElephantDrive
Auto-transfer from defunct Xdrive.
F-Secure
[Steek acquired by F-Secure July 2009]
Humyo
Humyo was acquired by Trend Micro and will become part of Trend Micro SafeSync. Humyo no longer accepts new clients.
IASO Backup
Advanced[clarification needed] data reduction technology. Data de-duplication mechanism. High level[clarification needed] of scalability and cost effectiveness.
ICFiles
Secure File Share Storage. Proprietary license download client. High level security, SOC 2 TYPE II, ISO 27001,27017, 27018, CSA, PCI, HIPAA, CJIS, EU Model Clauses, on request private servers for FISMA and FedRAMP.
Initial seed via a MiMedia-owned external hard drive available (no extra cost, shipping included).
Mozy
Data de-duplication; block-level incremental. "Mozy Data Shuttle" physical seeding service available for extra fee.
Replicalia
Professional Backup for Professional Data.
SpiderOak
Data de-duplication."Zero Knowledge" encryption.
StoreGrid Cloud
Byte-level incremental backup, local backup, Disk Image backup—BMR and physical seeding.
Syncplicity
Google Docs sync, Central Management with Business Console.
Tarsnap
Client source available; data de-duplication; block-level incremental.
TeamDrive
Store encrypted data on any WebDAV server; supports working offline; files can be commented; built-in support for conflict resolution.
Unitrends Vault2Cloud
Data de-duplication; hybrid on- and off-premises data backup; physical seeding.
UpdateStar Online Backup
Data de-duplication; block-level incremental.
Usenet backup
Is the method of storing backup data on the usenet.[91]
Windows Live Mesh
Replaces windows live sync and windows live folder.
Zetta Enterprise-grade Online Backup
Supports Linux, Mac OS, and Windows, high speed WAN optimization, SAS 70 certified data centers.
Zmanda Cloud Backup
Available in German and Japanese languages, supports MS SQL Server, MS Exchange, SharePoint, MySQL Database, System State, Oracle.
Versioning
Any changes can be undone, and files can be undeleted.
Acronis
Supports detailed history of changes to files with browsing by date or version number.
Backblaze
Old versions of files are kept for 30 days by default; One-year or Forever Retention is optional.[92]
Box
Versioning is included in paid subscription
Carbonite
Keeps old versions for up to three months. It keeps one version for each day of the past week, one version for each of the previous three weeks, and one version for each of the previous two months that the file has been backed up. Versioning available for PC computers only; not available for Mac.
CloudJuncxion
Supports multiple versions less than a week old, one version less than two weeks old, one version less than month old, and one version older than a month.
Crashplan
Options: All, or staged (daily, then weekly, etc.).
Cubby
All previous versions and deleted files are kept until explicitly removed by the user or the user runs out of space. All deleted files and previous versions count towards the storage limit.
Dolly Drive
Yes. Keeps unlimited versions of files.
Dropbox
By default, Dropbox saves a history of all deleted and earlier versions of files for 30 days for all Dropbox accounts.[93]
Dropmysite
Provides incremental backups with the ability to download every snapshot.
ElephantDrive
Any number of versions can be kept for any amount of time.
Google Drive
Old versions of files are kept for 30 days or 100 revisions. Revisions can be set not to be automatically deleted.
IASO Backup
All versions of files can be kept for different periods of time, starting from 1 month to 1 year or more.
ICFiles
No files are kept after delete, auto delete clears at every 24 hours.
iDrive
Up to 10 old versions of files are kept forever (until explicitly removed).
Mozy
Old version of files are kept for 30 days. Pro 60 days, Enterprise 90 days.[94]
PowerFolder
Five versions are kept online. In the client it is configurable how many versions to store locally.
SOS Online Backup (Infrascale)
All versions are kept. Only the largest counts towards the storage limit.
SpiderOak
All versions are kept. All files can be undeleted.
SugarSync
Five versions are kept. Only the most recent version of each of existing files as well as deleted files count towards the storage limit.
Sync.com
Sync.com saves a history of all deleted and earlier versions of files, 30 days for free accounts, indefinitely for premium plans.
Syncplicity
Old versions of files, as well as deleted files, are kept for 30 days. Configurable for business or enterprise-class services.
TeamDrive
All previous versions are kept and can be restored.
Tresorit
Versioning is included in paid subscription
Zetta Enterprise-grade Online Backup
All versions are kept. All files can be undeleted.
Other features and limitations
Other notable limitations or features.
Baidu Cloud
Must be registered by verified phone first.
Box
Performance degrades after 10,000 files in sync folder. Technical limit of 40,000 files in sync folder. Does not sync .tmp files, Outlook PST files, hidden files (hidden folders are synced), or any file or folder with \/*?":<>| in the name.[95]
CloudJuncxion
Decentralized fragment-and-disperse storage across a collection of heterogeneous clouds for maximal security. Supports a Virtual Private Cloud model for complete control by the enterprise customer. Supports Sync Groups for greater control over synchronization of files across multiple devices.
Dropbox
Performance degrades with more than 300,000 files in sync folder. This is a soft limit.[96]
Google Drive
All account types are limited to 750 GB upload bandwidth per day.[97] Enterprise accounts are now limited to 5 TB per paid user on the account whereas prior to May 2023 only a single user was required for the advertised unlimited storage. Once 5 users are on an Enterprise account, more storage can be requested in 25 TB allotments once every 90 days, but extra storage is not guaranteed. The extra allotted storage is also removed when users on the account drop under 5. Thus unlimited storage is unfeasible to attain with Google Drive's new restrictions.
Sugarsync
Limited to 80,000 files per top level sync folder. To work around, one can create multiple syncing folders, but each top level folder is limited to 80k files. Also, Microsoft outlook and Apple iTunes databases are unsupported.[98]
Trustbox
A 3-layer encrypted storage supports privacy for an unlimited file version retrieval. Restore any file from any point in time.[99]
Defunct services
Bitcasa closed its services in February 2017.[100]
^What is max file size for upload?Archived 2013-02-03 at the Wayback Machine"There is no maximum file size limit for adding the file through the SugarSync Manager application. However, there is a 100MB limit for files being uploaded through the SugarSync website."