Airship

Airship (formerly Urban Airship, founded 2009) is one of the original and most established push-notification providers, now positioned as a full "Customer Experience Platform" (AXP) spanning mobile push, web push, in-app messaging/Scenes, SMS, email, mobile wallet, and cross-channel Journeys orchestration. Its push API and SDKs are battle-tested at massive scale, the company claims having delivered over 3 trillion messages, and the platform layers on no-code experience editors, A/B testing, Predictive AI send-time optimization, and Performance Analytics. It is squarely an enterprise tool: pricing is custom/quote-only, with third-party estimates and OneSignal's own comparison citing roughly $35,000/year entry (around 250k monthly contacts, including an onboarding fee), scaling into six figures for global deployments.

Where Airship wins is depth, reliability at scale, and breadth of channels and targeting. Reviewers across G2 and Gartner Peer Insights consistently praise the rich segmentation, journey orchestration, cross-device preview, and responsive support; its push-notification capability scores 9.3/10 on G2's feature breakdown, and Gartner Peer Insights aggregates sit in the 4.4–4.8 range across marketing-platform categories. Where it loses is cost and complexity: it is widely described as one of the most expensive options in the space, the UI is criticized as inconsistent across channels, onboarding is lengthy/clunky, and performance analytics/reporting carry a real learning curve. It also historically lagged competitors on newer surfaces (web push arrived roughly two years after rivals).

For developers, Airship offers a mature REST API and broad first-party SDK coverage (iOS/tvOS/visionOS, Android/FireOS/TV, Web, plus React Native, Flutter, Cordova, Capacitor, Unity, Xamarin). API throughput is governed by documented rate limits and batch caps (max 100 push objects per batch, 1,000-user tag-update batches, 1,000-message throttle batches), and a paid "Boost" add-on parallelizes large segmented sends. The trade-off versus lighter providers like OneSignal is clear: more power, governance, and channel breadth, at materially higher price and integration effort, best for highly-resourced teams with dedicated engineering, not small/indie apps.