Command-line file transfer

A croc alternative with nothing running between the two machines

A code in a terminal, no account, open source, and a sender who does not want to think about networks. croc is the tool most people reach for when they want exactly what the s3nd CLI does.

How s3nd works croc

What croc is

In its own terms.

A Go command-line tool for sending files and folders between any two computers with a code phrase. It uses a PAKE for end-to-end encryption, a relay to get through NATs, resumes interrupted transfers, and ships as a single binary for every platform.

Side by side

Where they part ways.

	s3nd	croc
What it is	A CLI, a library and React hooks over your own S3 bucket	CLI file transfer with a code phrase
Where the data lives	Your bucket: S3, R2, MinIO, Scaleway, Wasabi	In transit only, through a relay
Both ends online at once	No. The code is redeemed later, until it expires	Yes
From inside your web app	Yes, through one route on your server	No
Accounts	None. The code is the whole handshake	None
Hosting	Your bucket, plus your server when a browser takes part	Public relay by default; self-hostable
Price	Free. You pay your storage provider for a few objects that expire	Free
License	MIT	MIT

The differences

What actually changes.

Live versus stored

croc streams while both ends are connected. s3nd stores the object and leaves; the code works later, from a machine that was off when the transfer was made.

A relay versus a bucket

croc uses a public relay by default and lets you run your own. s3nd uses the bucket you already have, with the provider’s durability, lifecycle rules and billing.

Resume and size

croc resumes a broken transfer and handles very large files well. s3nd does a single PutObject today, which is right for snapshots and ordinary files; multipart is on the roadmap.