Comparison
Inboxkitten is a lightweight open-source option. FastTempMail adds live inbox updates, multi-address sessions, custom expiry, and guaranteed data deletion. Here's the full picture.
Feature Comparison
Why Switch
Inboxkitten requires you to poll or refresh the page to check for new messages. FastTempMail pushes emails to your inbox the moment they arrive via server-sent events — important when you're waiting on a time-sensitive OTP.
Inboxkitten supports one address at a time. FastTempMail gives you up to 3 active addresses in a single tabbed session — useful for A/B testing sign-up flows or running parallel tests.
Inboxkitten uses a fixed session length. FastTempMail defaults to 6 hours and lets you choose anything from 10 minutes to 3 days — matching the actual lifespan you need rather than an arbitrary default.
FastTempMail permanently deletes every address and message when the session ends — no backups, no retention. Inboxkitten is an open-source project without the same server-side deletion guarantees.
Verdict
Inboxkitten is a capable open-source project, but it was built for basic use cases. If you need to manually refresh to see emails, can only manage one address at a time, and have no control over expiry, you'll hit its limits quickly.
FastTempMail was built for the same use case but taken further: live updates so you never miss a time-sensitive email, multiple addresses for parallel workflows, flexible expiry, and a hosted service with a clear deletion policy. It takes about 10 seconds to switch.