Transfer files from Amazon S3 to iCloud Drive
Server to server, without downloading anything to your computer.
How it works
Connect both accounts once. ShiftMyData then talks to Amazon S3 and iCloud Drive 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?
iCloud Drive exposes no checksum through its API, so files are compared on size and modification time. That is a limit of iCloud Drive rather than of the transfer, and it applies whichever tool you use.
Before you start
- The largest single file iCloud Drive accepts is 50 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; iCloud Drive 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
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 iCloud Drive
Apple publishes no official API for iCloud Drive. The connection uses an unofficial one, signed in with your Apple ID password and a code Apple shows on your device, and Apple can change it without notice -- so treat iCloud as best-effort rather than as something to schedule a nightly job against.
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 iCloud Drive the same way: enter your Apple ID and password, then the code Apple shows on one of your devices.
- 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 iCloud Drive 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?
iCloud Drive exposes no checksum through its API, so files are compared on size and modification time. That is a limit of iCloud Drive rather than of the transfer, and it applies whichever tool you use.
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). iCloud Drive takes single files up to 50 GB, and its own storage quota applies.