OneSignal
Send push notifications, email, SMS, and in-app messages via API.
Read docs Updated 2026-06-16
What is OneSignal?
OneSignal provides an API for delivering push notifications, email, SMS, and in-app messages to users.
It is useful for developers building applications that require multi-channel customer engagement and messaging.
What you can build with OneSignal
Mobile push notification campaigns
Trigger targeted push notifications to iOS/Android users based on in-app events or user segments via the REST API.
Multi-channel user onboarding
Combine in-app messages with email and SMS to guide new users through setup flows using a single API key.
Transactional alerts
Send time-sensitive SMS or push alerts for order confirmations, password resets, or system downtime.
Get started with OneSignal
- 1Sign up at onesignal.com and create a new app
- 2Copy your REST API key from the dashboard
- 3Add the OneSignal SDK to your mobile or web project
- 4Make an HTTPS POST request to /api/v1/notifications with the API key in the header
- 5Test delivery in the OneSignal dashboard
OneSignal: pros & cons
Pros
- +Single API for push, email, SMS and in-app
- +Simple API-key auth over HTTPS
- +Self-serve dashboard with quick setup
- +Broad platform SDK support
Cons
- –API key must be kept secure server-side
- –Advanced analytics require paid plans
- –Delivery depends on third-party push/email providers
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A self-serve platform that lets developers send push notifications, email, SMS, and in-app messages through one API.
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