App Passwords vs OAuth — Which Is Safer?
March 10, 2026 · 1 min read
When a third-party app wants access to your email, it needs some kind of credential. The two main methods are OAuth and App Passwords. They work very differently, and the difference matters more than most people realise.
OAuth: broad, delegated access
OAuth lets you grant an app access to your account without sharing your password. You click 'Sign in with Google' or 'Sign in with Yahoo', your provider asks what permissions to grant, and the app gets a token.
The problem: OAuth permissions are often broader than what the app actually needs. A cleanup tool might request access to read all emails, manage labels, and access your contacts — because those permissions are bundled. The app then has a persistent token that works until you revoke it.
App Passwords: narrow, revocable access
An App Password is a 16-character token you generate yourself in your email provider's security settings. It grants IMAP access only — the protocol for reading and moving emails. That's it. It can't access your contact list, account settings, or purchases.
You can revoke it in seconds. Some providers also automatically revoke App Passwords after periods of inactivity.
The security comparison
| App Password | OAuth | |
|---|---|---|
| Access scope | IMAP only | Varies — often broad |
| You control expiry | Yes — revoke anytime | Yes, but easy to forget |
| Auto-expires | Varies by provider | No — persists indefinitely |
| App can read contacts | No | Often yes |
| Password exposed | No | No |
| Provider data policies apply | No | Yes |
Which should you use?
For email cleanup tools, App Passwords are the better choice. They give the app exactly what it needs (IMAP access) and nothing more. If you ever want to disconnect the app, you revoke the App Password.
Klearbox uses App Passwords for exactly this reason. We support Yahoo Mail, iCloud, GMX, Web.de, T-Online, AOL, Yandex, and Zoho. We never ask for OAuth and we never request broad account access.