FTPS Connection Tester
Test Implicit or Explicit FTPS connections, verify TLS encryption is working, and inspect the server certificate — no software needed.
Looking for plain FTP?
This tool tests FTPS (FTP over TLS). For unencrypted FTP servers on port 21, use the FTP Connection Tester instead.
FTPS vs SFTP — what's the difference?
FTPS (FTP Secure) adds TLS encryption to the standard FTP protocol. It operates in two modes: Explicit FTPS (FTPES) starts unencrypted on port 21 and upgrades via the AUTH TLS command, while Implicit FTPS uses a dedicated TLS-only port (typically 990).
Common FTPS connection issues
- Certificate errors — self-signed or expired TLS certificate on the server side.
- TLS handshake failure — incompatible TLS versions between client and server.
- Passive mode data port blocked — the firewall is not forwarding the passive data ports.
- Wrong mode — connecting in Implicit mode to an Explicit-only port (or vice versa).