Expo Push

Expo Push is the push notification service bundled with the Expo platform for React Native apps. Rather than being a standalone messaging product, it is a free abstraction layer that sits in front of Apple Push Notification service (APNs) and Firebase Cloud Messaging (FCM): developers send a JSON payload (with an ExponentPushToken) to Expo's single REST endpoint, and Expo relays it to the correct underlying provider, normalizing the two very different platform APIs into one. The flow is asynchronous and two-stage, a synchronous "ticket" is returned immediately, and a "receipt" (fetched ~15 minutes later) reports the final delivery status from APNs/FCM. It is aimed squarely at React Native / Expo developers who want to ship cross-platform push without writing separate iOS and Android integrations or standing up their own delivery infrastructure.

Its biggest selling point is that the push service itself is genuinely free with no per-message charge, a sharp contrast to most commercial notification APIs. The trade-off is operational: there is no SLA, and the documented hard ceiling is 600 notifications/second per project, with payloads capped at 4096 bytes, batches of 100 messages per request, and receipt lookups of up to 1000 IDs. Delivery is "at-least-once" best-effort, meaning notifications can occasionally be duplicated or dropped, and the official guidance pushes responsibility onto the developer (implement throttling, exponential backoff, and receipt-checking). The expo-server-sdk-node library handles much of this automatically, but server SDKs for other languages (Python, PHP, etc.) are community-maintained rather than official.

In practice the service performs well for its price point. Third-party benchmarking by Knock (Mar–Jun 2026) recorded a p50 response time of 42ms, p90 of 73ms, and p99 of 254ms, with an average daily error rate of 0.16% and 52 of 91 days at zero errors, though a single April 9, 2026 incident spiked the error rate to 10.72%, illustrating the no-SLA risk. Expo Push is best understood as a high-leverage convenience for teams already in the Expo/React Native ecosystem; teams needing guaranteed delivery, advanced segmentation, analytics, or contractual uptime typically layer a commercial notification platform (Knock, Courier, OneSignal) on top of, or instead of, the raw Expo endpoint.