9 posts tagged with "Performance"

Galio is a UI toolkit and component framework for React Native that provides a consistent set of ready-made, themeable building blocks (buttons, cards, text, inputs, nav bars, etc.) so you can prototype and ship mobile UIs faster. The galio repository includes the core components and a lightweight theme system in src/theme (see colors.tsx, sizes.tsx, index.tsx) plus components under src/ such as Block, Button, Text, Input, Card, Avatar, NavBar and more.

Learn more on the official site: galio.io and browse the source and examples on GitHub: github.com/galio-org/galio.

Older Android phones expose every expensive choice in a React Native app: heavy startup work, oversized images, slow lists, chatty network calls, JS-thread animations, and debug-only assumptions. The goal is not to chase one magic setting. The goal is to measure on real hardware, reduce work on the critical path, and ship a release build that keeps memory, CPU, and frame time under control.

Memory leaks in React Native usually come from resources that outlive the screen that created them: timers, subscriptions, unresolved requests, sockets, navigation listeners, heavy lists, image caches, and native module handles. The fix is not a single package. It is a repeatable loop: reproduce the leak, profile it in a realistic build, remove the retained reference, and verify that memory returns to a stable baseline.

FlatList is fast when each row is cheap, keys are stable, virtualization is tuned for the screen, and the data layer avoids unnecessary re-renders. It becomes slow when rows contain heavy images, anonymous render functions, unstable item references, eager API calls, and too many mounted views. This guide focuses on practical fixes you can apply to production feeds, chats, catalogs, and marketplace screens.

React Native performance work should start with measurement, not guesses. Most slow apps are not slow everywhere. They are slow on a few screens: feeds, checkout, chat, onboarding, maps, image grids, video playback, or cold start.

Animated.View is the built-in React Native way to animate a view's opacity, transform, position, and other supported styles. It is still useful for simple microinteractions: fade-ins, scale feedback, loading motion, card entrance animations, and small transitions that do not need complex gesture logic.

For heavy gesture-driven UI, shared element transitions, and UI-thread worklets, React Native Reanimated is usually the better tool. For simple screen polish, the core Animated API is still enough.

Hermes is the JavaScript engine optimized for React Native. In modern React Native and Expo projects, Hermes is the default path for most apps, so the real question is no longer "How do I turn Hermes on?" It is "How do I confirm Hermes is working, benchmark the app properly, and avoid update/runtime mismatches?"

Video compression is one of the easiest ways to reduce upload time, storage cost, and feed latency in a React Native app. It matters for social networks, chat apps, marketplace listings, short video apps, fitness apps, and any product that lets users upload media from the camera roll.

Perceived performance is how fast an app feels to the user. A screen can take the same amount of time to load, but feel much faster when it shows immediate feedback, preserves user work, avoids blank states, and explains what is happening.