2Factor.in OTP API vs Alert21
| 2Factor.in OTP API | Alert21 | |
|---|---|---|
| Free plan | Yes | No |
| Free trial | No | No |
| Paid from | ₹4,999/mo | — |
| Open source | No | No |
| Platforms | Web | Web |
| Free plan | Yes | — |
| Pay-as-you-go | — | Yes |
| SMS API | — | Yes |
| Delivery status | — | Yes |
| Webhooks | — | Yes |
Both are listed in Best Transactional SMS Software. On Freedom251, 2Factor.in OTP API scores higher on our published basis.