Bolt performance

Slow Bundle Build Time - Build Takes Too Long

Your Bolt app takes minutes to build even with small changes. Development speed suffers with slow hot reload and rebuild times.

npm run dev or npm run build takes excessive time (over 30 seconds for simple changes).

Error Messages You Might See

Build taking over 60 seconds Hot module replacement slow Bundle size exceeded 500KB Compilation timeout
Build taking over 60 secondsHot module replacement slowBundle size exceeded 500KBCompilation timeout

Common Causes

  1. Too many dependencies or heavy packages being bundled
  2. Webpack/Next.js not optimized - missing splitting or lazy loading
  3. Large image assets in bundle instead of optimized
  4. Development mode compiling all unused code
  5. TypeScript checking every file on each change

How to Fix It

Analyze bundle: npm run build -- --analyze to see what's large

Remove unused dependencies: npx depcheck

Use dynamic imports for heavy libraries: import('heavy-lib').then(mod => mod.default)

Enable SWC minifier in next.config.js for faster builds

Split code: ensure lazy loading of routes and components

For dev: use --turbo flag if using Next.js 13+

Real developers can help you.

Matthew Butler Matthew Butler Systems Development Engineer @ Amazon Web Services Nam Tran Nam Tran 10 years as fullstack developer Bastien Labelle Bastien Labelle Full stack dev w/ 20+ years of experience Sage Fulcher Sage Fulcher Hey I'm Sage! Im a Boston area software engineer who grew up in South Florida. Ive worked at a ton of cool places like a telehealth kidney care startup that took part in a billion dollar merger (Cricket health/Interwell health), a boutique design agency where I got to work on a ton of exciting startups including a photography education app, a collegiate Esports league and more (Philosophie), a data analytics as a service startup in Cambridge (MA) as well as at Phillips and MIT Lincoln Lab where I designed and developed novel network security visualizations and analytics. I've been writing code and furiously devoted to using computers to make people’s lives easier for about 17 years. My degree is in making computers make pretty lights and sounds. Outside of work I love hip hop, the Celtics, professional wrestling, magic the gathering, photography, drumming, and guitars (both making and playing them) Rudra Bhikadiya Rudra Bhikadiya I build and fix web apps across Next.js, Node.js, and DBs. Comfortable jumping into messy code, broken APIs, and mysterious bugs. If your project works in theory but not in reality, I help close that gap. Kingsley Omage Kingsley Omage Fullstack software engineer passionate about AI Agents, blockchain, LLMs. 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. Matthew Jordan Matthew Jordan I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job. Basel Issmail Basel Issmail ’m a Senior Full-Stack Developer and Tech Lead with experience designing and building scalable web platforms. I work across the full development lifecycle, from translating business requirements into technical architecture to delivering reliable production systems. My work focuses on modern web technologies, including TypeScript, Angular, Node.js, and cloud-based architectures. I enjoy solving complex technical problems and helping teams turn product ideas and prototypes into working platforms that can grow and scale. In addition to development, I often collaborate closely with product managers, business analysts, designers, and QA teams to ensure that solutions align with both technical and business goals. I enjoy working with startups and product teams where I can contribute both as a hands-on engineer and as a technical partner in designing and delivering impactful software. Jen Jacobsen Jen Jacobsen I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses. I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain.

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Frequently Asked Questions

What's a good target build time?

Dev mode cold start: <10s. Hot reload: <2s. Full build: <20s

How do I find what's slowing builds?

npm run build -- --analyze or npm run build --profile to see bottlenecks

Does using less packages help?

Yes significantly. Each dependency adds parsing time. Prefer lighter alternatives or inline small utilities

Related Bolt Issues

Can't fix it yourself?
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