Performance Profiler (Android)
Checklist
Recompositions
- Composables only recompose when state changes
- State properly scoped with
remember - Stable item keys in LazyColumn
- Annotate custom data classes with
@Stableor@Immutable - Defer state reads (wrap in lambdas where possible)
- Avoid backwards writes (never write to a state that was already read higher in the same composable)
Lists
- Use
LazyColumnnotColumn + verticalScrollfor large data - Stable keys via
key()parameter - Lightweight item composables
Memory
- No memory leaks (avoid Activity/View refs)
- Use Coil/Glide for image loading with caching
- Proper lifecycle management
Body Computation
- No heavy work in composable body
- Use
rememberfor expensive calculations - Use
derivedStateOffor derived state
Quick Wins
| Issue | Fix |
|---|---|
| Parent recomposes | Extract stable child composables |
| Expensive body | Use remember or derivedStateOf |
| Unstable IDs | Use stable keys in LazyColumn |
| Memory leak | Avoid storing Activity/View references |
| Broad recomposition | Narrow state scope |
| Unstable custom types causing broad recompositions | Add @Stable/@Immutable |
| Backwards write or immediate state read | Defer with lambda or derivedStateOf |
Debug
Use Layout Inspector → Recomposition Counts to visualize recompositions Use Compose Compiler Metrics report (stability analysis) Enable Composition Tracing in Layout Inspector
Severity
- 🔴 Critical: Visible lag, leaks
- 🟡 Moderate: Noticeable impact
- 🟢 Minor: Optimization opportunity