Verdict · refreshed weekly
What is the best push notification API?
OneSignal leads overall on the APIbenchmarks Index (ABI 86.4, grade A). "Best" is not one number: Knock has the strongest documentation, Amazon SNS the best reliability, Amazon SNS the widest ecosystem, and OneSignal the easiest onboarding. This page reports all of it on the same criteria, fully reproducible.
01The ranking
Every provider scored on the same four criteria (0 to 100), highest ABI first. Click a provider for the full scorecard and sources.
| # | Provider | Documentation | Reliability | Ecosystem | Accessibility | ABI |
|---|---|---|---|---|---|---|
| 1 | 84 | 85 | 86 | 92 | 86.4A | |
| 2 | 82 | 92 | 88 | 80 | 85.6A | |
| 3 |  Amazon SNS | 78 | 95 | 90 | 72 | 84.1B |
| 4 | 90 | 80 | 76 | 88 | 83.6B | |
| 5 | 85 | 78 | 80 | 88 | 82.6B | |
| 6 | 80 | 78 | 70 | 90 | 79.0B | |
| 7 | 74 | 88 | 72 | 38 | 69.8C |
Scores are point-in-time and refresh weekly. Every cell is reproducible from the published inputs and formula. See the methodology →
02"Best" depends on what you optimize for
A provider can lead on one criterion and trail on another. Pick by the axis that matches your workflow.
| If you care about | The axis | Current leader |
|---|---|---|
| Overall quality | APIbenchmarks Index | |
| Documentation & developer experience | Documentation score | |
| Uptime & reliability | Reliability score |  Amazon SNS |
| SDK & language coverage | Ecosystem score | Amazon SNS |
| Getting started fast | Accessibility score | |
| A generous free tier | Free tier | OneSignal, Firebase Cloud Messaging, Amazon SNS, Knock, Courier, Expo Push |
03How to choose
Start from the ranking above instead of guessing, then run a quick check of your own: take the top two providers, read their docs, and call each once for your actual use case. A 30-minute hands-on test in your stack tells you more than any single headline number, because the right push notification API also depends on your budget and constraints, which the score deliberately leaves out.