FTPMonitor / Guides / Authentication failed

Authentication failed

Why FTP/SFTP authentication fails and how to correct credential, key, and account policy issues.

Diagnose this automatically

Verify whether authentication is the actual failure point.

terminal
npx ftpmonitor check --protocol sftp --host example.com --port 22 --username user --password pass
Shareable output
terminal
npx ftpmonitor check --protocol sftp --host example.com --port 22 --username user --password pass --format slack --copy

Prefer the browser? Run the same check on the homepage.

Authentication failures mean the server rejected your login attempt.

This can be wrong credentials, wrong protocol, key issues, or account restrictions like IP allowlists.

Common causes

  • Wrong username/password (hidden whitespace is common)
  • Account locked/disabled/expired
  • Server requires FTPS instead of FTP (or disallows plain FTP)
  • SFTP key auth required or wrong key/passphrase
  • IP allowlist / geo restrictions

Fix checklist

  1. Copy/paste credentials carefully and retry (watch trailing spaces).
  2. Confirm which protocol is required: FTP vs FTPS vs SFTP.
  3. If SFTP key auth is required, confirm the private key + passphrase and that the public key is installed server-side.
  4. Ask the server owner if there’s an IP allowlist restriction.
FTPMonitor Help

Still stuck? We can help diagnose and fix it.

Choose the level of help that matches the urgency. Never send passwords, private keys, or other secrets.

Fix Report
$49
A written diagnosis and recommended fix for one FTP, FTPS, or SFTP issue.
  • Written diagnosis
  • Recommended fix steps
  • Best for non-urgent issues
Recommended
Same-Day Help
$149
Priority troubleshooting for one active issue, with a clear same-day diagnosis and action plan.
  • Priority troubleshooting
  • Same-day diagnosis and action plan
  • Best for active business problems
Live Fix Call
$299
Live troubleshooting help for an urgent or unusually complex FTP, FTPS, or SFTP problem.
  • Live troubleshooting session
  • Best for urgent or complex failures
  • Scheduling coordinated after checkout
Related
  • FTP 530 Login incorrect — How to fix FTP 530 errors: bad credentials, account restrictions, FTPS requirements, and permission issues.
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