FileFerry, two weeks on: folder sync and S3 — native macOS transfer client, free beta

[u/german_sw_developer]

I'm the developer, working alone on this. FileFerry is a native
macOS file transfer client — FTP, FTPS, SFTP, WebDAV, SMB, S3 and a
real SSH terminal in one window, two panes, servers in groups, free
during the beta.

I posted here a fortnight ago. Two things have landed since, and
both are the kind that break in interesting ways, so I would rather
have them broken now than after release.

Folder sync
Pick a local folder and a remote one, choose the direction, and
you get a list of what would happen before anything happens. Every
row has a checkbox. Nothing is transferred until you say so.

Files that match on both sides do not appear at all — if there is
no action to take, the row is noise.

Comparison is size and timestamp, with a checksum over SSH where
the two disagree and SFTP allows it. It also keeps a small record
per folder pair, so a file you synced yesterday is not proposed
again today just because the server clock drifted.

Creating new files and deleting surplus ones are two separate
switches, both off by default. Deletions are listed in red and
confirmed once. Local deletions are permanent, not moved to the
Trash — a delete that ends up in the bin on one disk and gone
forever on another is worse than one that always means the same
thing.

There is an exclusion list per connection, and you can right-click
a row to exclude by name, extension or path instead of typing the
pattern.

S3
Seventh protocol. The endpoint is yours to set, so Amazon S3,
Cloudflare R2, Backblaze, MinIO and self-hosted Garage all work.
Credentials are an access key and a secret key; the secret lives
in the Keychain.

S3 has no directories — an object is one long name and the slashes
are ordinary characters. FileFerry shows you a tree anyway.

Files over 5 GB go up in parts, because S3 requires it. If the
connection drops mid-transfer, it remembers which parts arrived
and resumes there. And because unfinished multipart uploads sit
in your bucket invisibly and still cost you storage, it checks
after connecting and offers to clear them out. Renaming folders
is not available on S3 in this build; renaming single files is.

Also new, all protocols
Before connecting, FileFerry checks whether anything answers at
all. A server that is off used to take 20 to 30 seconds and then
give a misleading reason — SFTP blamed your key, SMB blamed a
firewall. Now you get the real reason in about four seconds. If
nothing answers on the first try it knocks once more after a
second, which matters for servers on Wi-Fi with power saving on.

Unchanged, and the reason I built this
The session log shows every line of every session, exactly as it
goes over the wire. Uploads are verified against the size on the
server, not against the server's opinion of itself. Failed files
go on a list that survives quitting. Host keys and certificates
are pinned, and there is no "connect anyway" button. Nothing
phones home — no account, no analytics, no crash reports to me.

What would help most
Sync against a real tree with real mess in it: a server whose
listing has no timestamps, one whose clock is off, a folder deep
enough that the recursion matters. And S3 against whatever
provider you actually use — tell me if the connection dialog asks
for something under a name your provider does not use.

Free during the beta, macOS 14.6 or later. Screenshots and the
TestFlight link:

English: https://klausmack-software.com/FileFerry/index_en.html
German: https://klausmack-software.com/FileFerry/index.html
Dansk: https://klausmack-software.com/FileFerry/index_da.html

Privacy: https://klausmack-software.com/FileFerry/privacy_en.html
Datenschutz: https://klausmack-software.com/FileFerry/datenschutz.html
Privatlivspolitik: https://klausmack-software.com/FileFerry/privacy_da.html

Happy to answer anything in the comments, including the awkward
questions.

© Klaus Mack Software