Both tools exist to keep your real address out of places you do not fully trust. The difference is what happens after the first message.
A temporary email is for one interaction
You use it, you read what arrives, and then it is gone. The entire point is that nothing persists. There is no address to manage, no alias to disable, no history to audit. If the site turns out to be sending spam, the inbox has already expired before the second message arrives.
An alias is for ongoing access with a buffer
An alias forwards to your real inbox. You keep the alias address as long as you want, and you can disable it when a sender starts abusing it. The key difference: the alias exists tomorrow, next week, next year. It is the right tool when you need continuity — a login you will use again, an account with purchase history, a newsletter you actually intend to read.
Side-by-side comparison
| Factor | Temporary email | Email alias |
|---|---|---|
| Setup time | Zero — instant on arrival | A few minutes (alias service account) |
| Persistence | Minutes to hours | Indefinite until disabled |
| Linked to real inbox | No | Yes (forwarding) |
| Can send from | No | Some alias services allow it |
| Block on blocklists | Yes (disposable domain) | Less common, harder to detect |
| Account recovery | Not possible | Yes |
| Best for | One-off verification, quick signups | Ongoing accounts, long-term logins |
The decision rule
If you would be upset to lose access to the account next week — use an alias. If you genuinely do not care what happens after today — use a temporary inbox. The failure mode of using temporary email for something that needed an alias is losing access permanently and having no recovery path.