Alert21
The facts below are what the maker publishes about Alert21, checked and dated. Our editors have not written about it yet.
Plans and prices
From Alert21's own pricing page, checked 24 Sep 2026.
| Plan | Price | What it gives you |
|---|---|---|
| SMS pay-as-you-go | Priced on request | Usage-based billing · Volume discounts as sending scale grows · Prepaid balance in Indian Rupees |
The facts
Each one read from Alert21's own pages, with the date it was checked.
The company
- Headquarters
- Greater Noida, Uttar Pradesh, Indiachecked 4 Oct 2026
Alternatives to Alert21
- 1

Mailchimp
Free planAndroidiOSWebAPI8.3From $13 a month - 2

Textmagic
Free planAndroidiOSWebAPI8.2Free plan - 3

ClickSend SMS API
AndroidiOSWebAPI8.1From $3.46 a month - 4
Commio SMS API
Free planAndroidiOSWebAPI7.9From $0.25 a month - 5
LINK Mobility SMS API
Free planAndroidiOSWebAPI7.9From zł49 a month - 6

Callr
AndroidiOSWebAPI7.6From €599 a month
