Transfer files from Amazon S3 to Dropbox

Server to server, without downloading anything to your computer.

How it works

Connect both accounts once. ShiftMyData then talks to Amazon S3 and Dropbox 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?

Amazon S3 offers MD5 and Dropbox offers Dropbox content hash — 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 Dropbox accepts is 350 GB. A bigger one is reported as failed and the rest of the transfer carries on.
Amazon S3 treats Report.pdf and report.pdf as two files; Dropbox treats them as one. Where both exist in one folder, only one arrives, so rename one first.
AWS bills data transferred out of S3 to the internet, after a small free allowance each month, so a large move out of S3 shows up on your AWS bill as well as on ours.
A transfer copies each file's current content, name and modification time; sharing and version history stay behind on Amazon S3. Business migration carries them where both sides support them.

Sources: docs.aws.amazon.com · aws.amazon.com · www.dropbox.com

Worth knowing about Amazon S3

S3 has no modification time of its own -- it records when an object was written, not when the file was authored, and that timestamp cannot be set. Transfers into S3 therefore compare on checksum where one is shared, and on size where one is not.

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.

Steps

On the Clouds screen, add Amazon S3: paste an access key ID and secret access key from the AWS console, ideally for an IAM user limited to the buckets involved.
Add Dropbox the same way: sign in with Dropbox and allow access.
Pick the source bucket or prefix in the left pane and the destination folder 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 Amazon S3 first?

No. The transfer is streamed from Amazon S3 to Dropbox 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). Dropbox takes single files up to 350 GB, and its own storage quota applies.

Move a folder now