We're building Expo Observe, a new way to understand how your app performs in the real world.
The problem
You ship your app, but do you know how fast it actually launches for your users? What about users on older devices or slower networks? When you push an update, does performance improve or regress? Did adding all those new libraries slow down your app?
These questions are hard to answer without dedicated tooling, and existing solutions often require significant setup or don't integrate well with the React Native ecosystem.
Debugging performance in React Native has been a long-standing difficulty: a challenge the React Native team have recently addressed with the new DevTools and Performance panel, but these are development-time tools. With Observe, we focus on tracking performance in production.
What Expo Observe does
In this initial Preview release, we’ve focused on tracking startup metrics for your app:
- Cold Launch time: launch time when the app's native code and resources are not in memory
- Warm Launch time: launch time when native libraries, app's state and resources are already cached in memory
- Time to Interactive: when your app is ready for user input
- Time to first render: when content first appears on screen
- Bundle load time: how long it takes to load your JavaScript
How it works
Once integrated, Observe collects these metrics from real user sessions and gives you tools to understand them:
- Track across releases: compare performance between builds and OTA updates to catch regressions early
- Statistical breakdowns: view median, average, min, max, and percentile values (P90, P99) for each metric
- Investigate outliers: when something looks off, dig into individual sessions to see all events, device info, and metadata for that user
What's next
This is just the beginning. We're starting with startup metrics because they're critical to user experience and retention, but we have plans to expand Observe's capabilities based on what we learn from early testers.
We're looking for developers to help us test and shape Expo Observe. If you're interested in early access, please join the waitlist by filling out the form below.