Authenticator.cc is one of those add‑ons that does exactly what you want without overcomplicating things. The interface is clean and simple, making it easy to scan codes or manage multiple accounts without extra clutter. What really makes it stand out, though, is how effortless the import and export process is. Whether you paste in plain text otpauth links or drop in a JSON backup, it just works — which is something many other authenticators stumble on.

Another strong point is that everything is stored locally in your browser profile. There’s no forced cloud sync or hidden upload, so you stay in control of your secrets. That said, it does mean you need to back up your codes yourself, since Firefox Sync won’t carry them over automatically. For some, that might be a downside, but the add‑on balances it out by offering encrypted backup options you can save to Google Drive or another service.

Overall, Authenticator.cc is lightweight, reliable, and refreshingly straightforward. It pairs well with a dedicated mobile app like Aegis for long‑term storage, while giving you the convenience of browser‑based codes when you need them. It may not have the flashy UI or advanced grouping of bigger apps, but if you want simple, open‑source, and import‑friendly 2FA in Firefox, it’s hard to beat.