📱 Mobile

Crash Rate

crash rate · app crash rate · crash-free sessions · crash free users · app stability · mobile crash rate

Definition

Crash rate is the share of app sessions that terminate abnormally; a core stability indicator that affects store ranking and user retention.

What crash rate is

Crash rate is the percentage of app sessions that end abnormally, with the process force-closed. An
abnormal termination can be caused by an unhandled exception, a memory error, misbehaviour in an
external SDK or a fault in native code.

Crash Rate = sessions with a crash / all sessions x 100%
Crash-Free Rate = 100% - Crash Rate

Google Play measures the crash-free sessions rate. The threshold for keeping a full rating is
98.91% or better, which is a crash rate at or below 1.09%.

How to diagnose the source of crashes

Tool	What it gives you
Firebase Crashlytics	Symbolicated stack traces, grouping by issue, trends
Google Play Console	Crash rate and ANR rate in production, version comparison
App Store Connect	The iOS crash reporter, integrated with Xcode Organizer
Sentry	Cross-platform, with React Native and Flutter support

The key data for diagnosis: app version, OS version, device, stack trace and frequency. A crash
should be prioritised on the number of affected users, not the number of incidents.

Crash rate after an SDK integration

A common scenario: a retailer integrates a personalization or analytics SDK and the crash rate
climbs. The usual causes:

Memory leaks — the SDK holds objects in memory and never releases them
Thread safety — the SDK touches UI elements from a background thread
Incompatible dependencies — version conflicts between shared libraries
Initialisation timing — the SDK initialises before the app is ready

Important: if crash rate rises after a release containing a new SDK, check the correlation by
date and version immediately. If the pattern matches, roll the SDK back while you investigate
rather than waiting for the next scheduled release.

Impact on business metrics

Crashes do more than irritate — they feed straight into app economics:

Users who hit a crash are more likely to delete the app, which raises CAC
A low store rating reduces organic installs
Crashes at checkout are a direct loss of conversion
Negative reviews affect ASO and trust in the brand

A crash rate at or below 0.5% is the target for e-commerce apps with active transactions.

Frequently asked questions

How is crash rate calculated?

Crash rate = (sessions with a crash / all sessions) x 100%. An alternative is the crash-free users rate: the share of users who never hit a crash. The second version is less distorted by heavy users with a large number of sessions.

What crash rate is acceptable?

The industry reference point is a crash-free sessions rate of 99% or better, meaning a crash rate at or below 1%. Google Play treats an app as stable at a crash rate at or below 1.09%. Above 2%, both Google and Apple reduce visibility in the store.

How does crash rate affect business metrics?

There is a direct correlation with retention: users who hit a crash delete the app two to three times more often. It also affects the store rating through reviews, the cost of support and the cost of re-acquisition.

How does an ANR differ from a crash?

A crash is an abnormal termination of the app, caused by an exception or a memory error. An ANR (Application Not Responding) is a freeze without termination, where the app stops responding for more than five seconds. Both are tracked in the Google Play Console, but they have different causes and different fixes.