Alert21 vs MessageFlow SMS API
| Alert21 | MessageFlow SMS API | |
|---|---|---|
| Free trial | Yes | |
| Platforms | Web | api, Web |
| Pay-as-you-go | Yes | |
| SMS API | Yes | Yes |
| Delivery status | Yes | Yes |
| Webhooks | Yes | Yes |
| Free plan | No | |
| Two-way messaging | Yes | |
| Monthly message limit | 0 messages/mo |
Listed together in Best Transactional SMS Software