Bolt performance

Large Bundle Size - App Loads Slowly

Your JavaScript bundle is very large (over 500KB), making the app slow to load. First Contentful Paint takes several seconds even on good connections.

Users on slow networks experience long loading times.

Error Messages You Might See

Bundle size 750KB (over limit) First Contentful Paint 8 seconds Large Cumulative Layout Shift Slow interaction to Next Paint
Bundle size 750KB (over limit)First Contentful Paint 8 secondsLarge Cumulative Layout ShiftSlow interaction to Next Paint

Common Causes

  1. Importing entire library when only small part needed
  2. Large image assets embedded in bundle instead of loaded separately
  3. Unused code not being tree-shaken by build tool
  4. Moment.js or similar heavy date libraries (use date-fns, dayjs instead)
  5. Loading all routes upfront instead of code splitting by route

How to Fix It

Use tree-shakeable imports: import { map } from 'lodash-es' not import lodash

Lazy load heavy components: const Component = dynamic(() => import('@/components/Heavy'))

Replace heavy libraries: moment.js -> date-fns or dayjs, @apollo/client -> urql

Optimize images: use next/image, convert to WebP, serve appropriate sizes

Enable code splitting in Next.js config (automatic for routes)

Real developers can help you.

Alvin Voo Alvin Voo I’ve watched the tech landscape evolve over the last decade—from the structured days of Java Server Pages to the current "wild west" of Agentic-driven development. While AI can "vibe" a frontend into existence, I specialize in the architecture that keeps it from collapsing. My expertise lies in the critical backend infrastructure: the parts that must be fast, secure, and scalable. I thrive on high-pressure environments, such as when I had only three weeks to architect and launch an Ethereum redemption system with minimal prior crypto knowledge, turning it into a major revenue stream. What I bring to your project: Forensic Debugging: I don't just "patch" bugs; I use tools like Datadog and Explain Analyzers to map out bottlenecks and resolve root causes—like significantly reducing memory usage by optimizing complex DB joins. Full-Stack Context: Deep experience in Node.js and React, ensuring backends play perfectly with mobile and web teams. Sanity in the Age of AI: I bridge the gap between "best practices" and modern speed, ensuring your project isn't just built fast, but built to last. BurnHavoc BurnHavoc Been around fixing other peoples code for 20 years. Nam Tran Nam Tran 10 years as fullstack developer Omar Faruk Omar Faruk As a Product Engineer at Klasio, I contributed to end-to-end product development, focusing on scalability, performance, and user experience. My work spanned building and refining core features, developing dynamic website templates, integrating secure and reliable payment gateways, and optimizing the overall system architecture. I played a key role in creating a scalable and maintainable platform to support educators and learners globally. I'm enthusiastic about embracing new challenges and making meaningful contributions. Anthony Akpan Anthony Akpan Developer with 8 years of experience building softwares fro startups Richard McSorley Richard McSorley Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures. 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.** PawelPloszaj PawelPloszaj I'm fronted developer with 10+ years of experience with big projects. I have small backend background too Jared Hasson Jared Hasson Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever AUXLE AUXLE I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies.

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Frequently Asked Questions

What's a good target bundle size?

JavaScript: <200KB. With gzip: <50KB. For comparison, heavy frameworks are ~200KB

How do I check actual bundle size?

npm run build shows Next.js Size. Use webpack-bundle-analyzer for detailed breakdown

What about image sizes?

Use next/image for automatic optimization. Aim for <100KB total images, <30KB per image

Related Bolt Issues

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