Transfer files from Dropbox to Backblaze B2

Server to server, without downloading anything to your computer.

How it works

Connect both accounts once. ShiftMyData then talks to Dropbox and Backblaze B2 directly and streams the files between them in memory — nothing is written to our disks, and nothing travels down to your machine and back up again. The job runs on a worker, so closing the tab does not stop it.

Will every file be verified?

Dropbox offers Dropbox content hash and Backblaze B2 offers SHA-1 — no checksum in common. Files are compared on size and modification time instead, which is the same basis every other tool uses for this pair; nobody can do better, because the two providers do not share a hash to compare.

Before you start

The largest single file Backblaze B2 accepts is 10 TB. A bigger one is reported as failed and the rest of the transfer carries on.
Backblaze B2 has no real folders, only names with slashes in them, so empty folders are not created there. Every folder that holds a file arrives as expected.
On a mirror into Backblaze B2: a B2 bucket keeps every version by default: a file overwritten or deleted by a mirror becomes a hidden version that is still stored and billed until a lifecycle rule removes it.
A transfer copies each file's current content, name and modification time; sharing and version history stay behind on Dropbox. Business migration carries them where both sides support them.

Sources: www.dropbox.com · www.backblaze.com · www.backblaze.com

Worth knowing about Dropbox

Dropbox uses its own block-based content hash rather than a standard one, so a checksum comparison works Dropbox-to-Dropbox and not otherwise.

Worth knowing about Backblaze B2

B2 charges nothing for uploads, and downloads are free up to three times what you store in a month, which makes it a cheap destination. Moving a whole archive back out in one month can pass that allowance, so check before you start.

Steps

On the Clouds screen, add Dropbox: sign in with Dropbox and allow access.
Add Backblaze B2 the same way: paste an application key ID and key from the Backblaze console, ideally one limited to the bucket involved.
Pick the source folder in the left pane and the destination bucket in the right.
Choose a mode — copy, mirror, move, or two-way — and start the transfer.
Leave it. Progress is on the Jobs screen, and a webhook can tell you when it ends.

Questions

Do I have to download my files from Dropbox first?

No. The transfer is streamed from Dropbox to Backblaze B2 on our servers, so nothing is written to your machine and your home upload speed is not the limit.

What happens if I close my laptop?

The job keeps running. It is queued on a worker rather than in your browser, and the progress is there when you come back.

How do I know every file arrived?

Is there a size limit?

None imposed by us. What you move is drawn from your prepaid allowance (30 GB free, then 500 GB for ₹100 or 2,500 GB for ₹500, each valid a year). Backblaze B2 takes single files up to 10 TB, and its own storage quota applies.

Move a folder now