What is the crash-free rate and where do I see it?

How it is calculated

Crash-free share = 1 − users who crashed ÷ active users, for the selected period.

Sample: 12,000 active users this week, 84 of them hit at least one crash. Crash-free share = 1 − 84 ÷ 12,000 = 99.3%.

It counts users, not crashes. One user who crashes ten times lowers it as much as a user who crashes once; the separate crash count shows how often it happened.

Where to find it

• Apps: App analyticsQuality & attributionStability
• Mini programs: Mini program analyticsDevice & qualityStability

The page also shows crash count, ANRs, UI freezes, app starts, the median cold and hot start time, and memory. Errors are grouped, and each group can be marked active, resolved or ignored.

Crash, ANR and UI freeze

ANRs and UI freezes are reported separately; they do not lower the crash-free share.

What does not count

• Custom errors you send with $app_error show in error groups but do not affect crash-free share.
• Crashes are only counted when the SDK reports them. Check your SDK's page for whether crashes are captured automatically or need to be turned on; do not assume every SDK sends $app_crashed by default.

Find the version behind a drop

1. Open App analyticsVersions & channels and compare crashes per version.
2. If one release stands out, open its error groups on the stability page.
3. Mark the release on the chart with an annotation; app versions are added as release annotations automatically.

If numbers look stale after a fix to historical data, use Recompute (last 7 days) on the stability page. To be told when stability gets worse, create a monitor on errors or error rate.

See also: Improve app performance.

See also

• How do I track app versions?