You can move to a new cloud backup service without losing files by keeping the old backup available until you have checked the new copy and tested that important files open. First confirm what the old service actually contains, then choose a transfer route that fits your data volume and available storage, verify the destination, and only afterward cancel or transfer the old account.
What kind of “cloud backup” are you moving?
The term can mean a computer-backup product, a cloud drive that syncs files across devices, or object storage used for larger datasets. These are not interchangeable: each may store different content and handle downloads, metadata, versions, and account cancellation differently. Check the exact source and destination documentation before choosing a method.
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In particular, a synced folder visible on your computer may contain online-only placeholders rather than the actual file contents. A backup product cannot necessarily back up data that is not stored locally. Backblaze’s April 2026 explanation describes this limitation for some Windows Dropbox and OneDrive folders in its Computer Backup product, while saying that product supports iCloud Drive and Google Drive. Those details apply to that product, not all backup services. Backblaze’s explanation of cloud-sync and backup behavior.
How do I move my files without losing them?
1. Inventory what must move
List the computers, external drives, synced and shared folders, and application data you need. Separate files that are physically present from cloud-only items. Check whether the source backup includes the relevant folders and whether it has finished updating; do not assume a general computer-backup plan captures every virtual or cloud-only file.
#1 Best Overall
- Easily store and access 2TB to content on the go with the Seagate Portable Drive, a USB external hard drive
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop
- To get set up, connect the portable hard drive to a computer for automatic recognition no software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
2. Confirm the old backup is usable
Before changing plans or accounts, open the source service’s backup or restore view. Check for expected folders and a sample of important files, and confirm the backup status is current. Backblaze’s migration guidance similarly recommends verifying the backup before restoring or migrating. Backblaze’s migration guidance.
3. Make a second recoverable copy
If the original files are still on a computer or drive, copy them locally to the new destination or to temporary storage before relying on a cloud-to-cloud transfer. A portable external hard drive can serve as staging storage if it has enough room, but it is not required when the files are already available elsewhere.
Rank #2
- Easily store and access 5TB of content on the go with the Seagate portable drive, a USB external hard Drive
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop
- To get set up, connect the portable hard drive to a computer for automatic recognition software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
If the old service is the only place the files remain, restore or download them before proceeding. Backblaze says its Online Backup service is not designed for rapid device-to-device migration; the provider describes direct local or wired transfer as generally significantly faster than downloading and uploading through its service. Actual speed depends on the devices, connection, and data volume. Backblaze’s migration guidance.
4. Choose a transfer route that fits the data
| Route | Best fit | What to check |
|---|---|---|
| Local copy, then upload or sync | The files remain on a computer or drive, and the dataset fits available local storage. | Confirm that the destination client uploads the intended folders and reports no unresolved errors. |
| Restore or download, then upload | The old service is the only surviving copy. | Allow time and storage for the restore; retain the downloaded copy until destination checks pass. |
| Cloud-to-cloud integration or migration service | A large dataset or a source/destination combination supported by a migration tool. | Verify endpoint support, permissions, metadata handling, versions, encryption or key requirements, fees, transfer reports, and how you can test the result. |
For example, Backblaze’s B2 documentation describes a provider-specific set of upload and migration routes. Its observed October 2026 documentation says files below 500 MB can be uploaded through its web UI, while larger files require an integration; it also describes a Flexify route for moving less than 50 TB from Amazon S3 to B2. These are B2-specific rules and options, not general cloud-migration limits. Backblaze B2 upload and migration options.
Rank #3
- Easily store and access 1TB to content on the go with the Seagate Portable Drive, a USB external hard drive.Specific uses: Personal
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop. Reformatting may be required for Mac
- To get set up, connect the portable hard drive to a computer for automatic recognition no software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
5. Check that the destination copy works
Compare expected directories and files with what appears at the destination. Review failed-upload or sync queues, then open representative files, including large files and any formats that are especially important to you. A file listing alone does not prove that every file is intact.
For high-value data, keep both the source and any staging copy until verification is complete. If both endpoints provide comparable checksums, you can compare them to check that file contents match. Do not assume a provider’s checksum feature applies to every transfer: Backblaze describes MD5 byte-for-byte checking for its Universal Data Migration service specifically. Backblaze’s cloud-migration service.
Rank #4
- Easily store and access 4TB of content on the go with the Seagate Portable Drive, a USB external hard drive.Specific uses: Personal
- Designed to work with Windows or Mac computers, this external hard drive makes backup a snap just drag and drop
- To get set up, connect the portable hard drive to a computer for automatic recognition no software required
- This USB drive provides plug and play simplicity with the included 18 inch USB 3.0 cable
- The available storage capacity may vary.
6. Retire the old backup only after verification
Check the old provider’s cancellation, data-retention, version-history, and account-transfer terms for your plan and region. If a control may delete the old backup, restore anything you still need before using it. In one Backblaze-specific example, “Inherit Backup State” resumes a prior backup, while “Transfer License” starts a new one and deletes the old backup; Backblaze advises restoring needed data first. Other providers may use different controls and retention rules. Backblaze’s explanation of its license-transfer options.
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Which transfer route should I choose?
- The original files are local: A local copy can avoid a cloud download-and-upload round trip, but requires enough local storage and compatible devices.
- The old service is the only copy: Restore or download first; do not cancel or trigger an account action that could remove the backup before you have another usable copy.
- The dataset is large: Compare the time and storage needed for local staging with supported cloud-to-cloud tools or a managed service. Check costs, access scope, and verification features rather than assuming a tool supports both providers.
- The folders are synced: Confirm that files are downloaded locally and that the backup product includes those folders; placeholders may not contain data to transfer.
- The data is business-critical, regulated, or very large: Use a documented migration plan, preserve source and staging copies, review security and access permissions, and consider a specialist.
Backblaze’s migration page describes support for several cloud drives and physical sources, and its B2 documentation names integrations for particular workflows. Those are examples of service-specific scope, not a universal guarantee that any migration tool will preserve every file, version, permission, or metadata field. Backblaze migration service details and B2 migration options.
Quick Recap
Best Value
- Plug-and-play expandability
- SuperSpeed USB 3.2 Gen 1 (5Gbps)
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