croc
croc v11.0.1 is a cross-platform command-line tool for transferring files and folders with a shared code, relay support, end-to-end encryption and resumable transfers.
What croc provides
croc lets one device send a file or folder and another device receive it with a short one-time code. Relay support helps devices connect across networks without users opening a local server, while the session uses authenticated key exchange and encrypted transfer. The code is a session credential, not a public share link.
Transfer and trust boundaries
Keep the code separate from the file and send it through a trusted channel. The receiver should confirm the file names, sizes and destination before accepting. Relays solve connectivity, but they do not grant permission to transmit arbitrary data or make a public network appropriate for sensitive material.
Resume and verification
Interrupted transfers may resume when both clients, the file and the session still match. A completion message does not replace a checksum or an application-level verification for executables, archives and backups. For long-term sharing, a permissioned storage system may be easier to audit than a one-time transfer. Review date: 2026-08-23.
Save to your cloud drive
Open the cloud drive to get the file directly, or save it for convenient access on another device.
Quark Cloud Drive
RecommendedSave croc to this cloud drive
Baidu Netdisk
Save croc to this cloud drive
croc 11.0.1 encrypted file transfer guide
Install the Windows x64 client, test a small harmless file, send the code through a separate trusted channel and verify the received result before using large or sensitive files.
Before you start
- Prepare compatible croc clients on both devices and confirm that their networks can reach the relay.
- Review the file for credentials, personal data or controlled information before sending.
- Choose a separate trusted channel for the one-time code and never publish the file and code together.
Installation steps
- 01
Extract the Windows package
Unzip the v11.0.1 Windows x64 archive into a fixed directory and run the version or help command in PowerShell.
- 02
Add the tool to PATH only when useful
Add the directory to the user PATH for repeated work; for a one-off transfer, run it from the current directory to avoid multiple versions.
- 03
Complete a small-file test
Test sending, code delivery, the receive directory and network reachability with a harmless small file before handling a folder or large archive.
Quick start
- 01
Send a file or folder
Start a send operation with the selected path and keep the sender running until the receiver connects and the transfer completes.
- 02
Receive after checking the prompt
Enter the code on the other device, inspect the listed names, sizes and destination, then approve the receive operation.
- 03
Verify the result
Check file count, size and openability; compare a hash for an executable, backup or important archive and keep the code out of shell history when possible.
Usage tips
- Organize names before sending multiple files and let the receiver confirm the complete list.
- Relay connectivity is not a substitute for data classification, authorization or retention rules.
- Test overwrite flags in a separate directory because an automated command can replace same-name files.
Troubleshooting and uninstall
Why does entering the code never connect?
Check that the code is complete, both processes are still running and a firewall, proxy or network policy is not blocking the relay. Re-test with a small file and a normal network.
What if a same-name file already exists?
Use a new receive directory or keep both versions until their contents are compared. Do not enable overwrite before the destination has been reviewed.
- Clear temporary credentialsRemove the executable directory and clean unneeded codes from terminal history, chats and temporary files after the transfer is verified.
Frequently asked questions
Do both croc devices need to be on the same LAN?
No. A relay can help the devices connect across networks, although both sides still need access to the relay and a suitable network policy.
Can I publish the transfer code with the file?
Treat the code as a session credential and send it separately through a trusted channel. Anyone who obtains it may attempt to receive the file.
Does the download require an extraction code?
The Quark entry does not require one; the four-character code for the Baidu entry is shown beside its download entry.