Cursor performance

React Components Rerendering Excessively

After Cursor refactored your React component code, components are re-rendering far too frequently, causing performance degradation and jank on the page.

Components that shouldn't re-render are being triggered by parent updates.

Error Messages You Might See

Component re-rendering too frequently Lag on user input High CPU usage Janky scrolling
Component re-rendering too frequentlyLag on user inputHigh CPU usageJanky scrolling

Common Causes

  1. Props or state objects recreated on every render (inline object/function creation)
  2. useCallback or useMemo removed to simplify code, eliminating optimization
  3. Parent passes new object reference every render even if contents identical
  4. Incorrect dependency arrays in useEffect (missing dependencies)
  5. Context consumer re-renders when context value changes (even unrelated)

How to Fix It

Use React DevTools Profiler to identify re-renders. Wrap components with React.memo() for prop comparison. Use useCallback/useMemo for functions/objects passed as props. Check dependency arrays. Split context if some parts change frequently.

Real developers can help you.

Yovel Cohen Yovel Cohen I got a lot of experience in building Long-horizon AI Agents in production, Backend apps that scale to millions of users and frontend knowledge as well. Simon A. Simon A. I'm a backend developer building APIs, emulators, and interactive game systems. Professionally, I've developed Java/Spring reporting solutions, managed relational and NoSQL databases, and implemented CI/CD workflows. rayush33 rayush33 JavaScript (React.js, React Native, Node.js) Developer with demonstrated industry experience of 4+ years, actively looking for opportunities to hone my skills as well as help small-scale business owners with solutions to technical problems Caio Rodrigues Caio Rodrigues I'm a full-stack developer focused on building practical and scalable web applications. My main experience is with **React, TypeScript, and modern frontend architectures**, where I prioritize clean code, component reusability, and maintainable project structures. I have strong experience working with **dynamic forms, state management (Redux / React Hook Form), and complex data-driven interfaces**. I enjoy solving real-world problems by turning ideas into reliable software that companies can actually use in their daily operations. Beyond coding, I care about **software quality and architecture**, following best practices for componentization, code organization, and performance optimization. I'm also comfortable working across the stack when needed, integrating APIs, handling business logic, and helping transform prototypes into production-ready systems. My goal is always to deliver solutions that are **simple, efficient, and genuinely useful for the people using them.** Bastien Labelle Bastien Labelle Full stack dev w/ 20+ years of experience Luca Liberati Luca Liberati I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture AUXLE AUXLE I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies. Stanislav Prigodich Stanislav Prigodich 15+ years building iOS and web apps at startups and enterprise companies. I want to use that experience to help builders ship real products - when something breaks, I'm here to fix it. Mehdi Ben Haddou Mehdi Ben Haddou - Founder of Chessigma (1M+ users) & many small projects - ex Founding Engineer @Uplane (YC F25) - ex Software Engineer @Amazon and @Booking.com Krishna Sai Kuncha Krishna Sai Kuncha Experienced Professional Full stack Developer with 8+ years of experience across react, python, js, ts, golang and react-native. Developed inhouse websearch tooling for AI before websearch was solved : )

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Frequently Asked Questions

How do I find unnecessary re-renders?

React DevTools Profiler tab. Highlight updates shows which components re-rendered. Check props/state actually changed.

What's React.memo?

HOC that memoizes component. Re-renders only if props change (shallow comparison). Use for expensive components.

Related Cursor Issues

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