Bolt storage

Image Compression and Optimization Not Working in Bolt App

Your Bolt.new application loads images at full resolution regardless of display size, causing slow page loads, excessive bandwidth usage, and poor Core Web Vitals scores. A 5MB profile photo is served at 4000x3000 pixels even though it's displayed at 100x100 on the page.

Bolt's AI typically generates basic img tags or stores images exactly as uploaded without any processing. This means a user uploading a 10MB DSLR photo gets that exact 10MB file served to every visitor, even on slow mobile connections.

The problem compounds quickly: a page with 20 user-uploaded images can require 50MB+ of downloads, making your app unusable on mobile and destroying your Google PageSpeed score. Image optimization is one of the biggest performance wins for any web application.

Error Messages You Might See

LCP (Largest Contentful Paint) exceeded 4 seconds Warning: Image with src has no width or height Error: sharp module not found in production net::ERR_CONTENT_LENGTH_MISMATCH (large image transfer failed)
LCP (Largest Contentful Paint) exceeded 4 secondsWarning: Image with src has no width or heightError: sharp module not found in productionnet::ERR_CONTENT_LENGTH_MISMATCH (large image transfer failed)

Common Causes

  • No image processing on upload — Images are stored at original resolution and format without server-side resizing or compression
  • Missing Next.js Image component — Using plain <img> tags instead of Next.js <Image> which provides automatic optimization
  • No lazy loading — All images load eagerly on page load, even those below the fold that aren't visible yet
  • Wrong image format — Serving PNG or JPEG instead of modern WebP or AVIF formats that are 30-50% smaller
  • No responsive sizing — Serving the same large image regardless of the user's screen size or viewport

How to Fix It

  1. Use Next.js Image component — Replace <img> with <Image> which auto-optimizes: <Image src={url} width={400} height={300} quality={80} />
  2. Compress on upload — Process images server-side before storage using sharp: sharp(buffer).resize(1200, 1200, { fit: 'inside' }).webp({ quality: 80 }).toBuffer()
  3. Use Supabase image transforms — Serve optimized images via transform URL: supabase.storage.from('images').getPublicUrl(path, { transform: { width: 400, quality: 80 } })
  4. Add lazy loading — Add loading="lazy" to images below the fold, or use the IntersectionObserver API for custom lazy loading
  5. Generate multiple sizes — Create thumbnail, medium, and full-size versions on upload and serve the appropriate one using srcset
  6. Set proper cache headers — Configure Cache-Control: public, max-age=31536000, immutable for static image assets

Real developers can help you.

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. 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 Taufan Taufan I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms. Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact. 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. 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. Milan Surelia Milan Surelia Milan Surelia is a Mobile App Developer with 5+ years of experience crafting scalable, cross-platform apps at 7Span and Meticha. At 7Span, he engineers feature-rich Flutter apps with smooth performance and modern UI. As the Co-Founder of Meticha, he builds open-source tools and developer-focused products that solve real-world problems. Expertise: 💡 Developing cross-platform apps using Flutter, Dart, and Jetpack Compose for Android, iOS, and Web. 🖋️ Sharing insights through technical writing, blogging, and open-source contributions. 🤝 Collaborating closely with designers, PMs, and developers to build seamless mobile experiences. Notable Achievements: 🎯 Revamped the Vepaar app into Vepaar Store & CRM with a 2x performance boost and smoother UX. 🚀 Launched Compose101 — a Jetpack Compose starter kit to speed up Android development. 🌟 Open source contributions on Github & StackOverflow for Flutter & Dart 🎖️ Worked on improving app performance and user experience with smart solutions. Milan is always happy to connect, work on new ideas, and explore the latest in technology. Victor Denisov Victor Denisov Developer Antriksh Narang Antriksh Narang 5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies. 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. 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.

You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.

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Frequently Asked Questions

What image format should I use for web?

Use WebP as the default format - it provides 30% smaller files than JPEG at the same quality. For maximum compression, use AVIF (50% smaller than JPEG). Always provide a JPEG fallback for older browsers using the picture element.

How do I optimize images already in my storage bucket?

Use Supabase's built-in image transformation API to serve optimized versions without re-uploading. Add transform parameters to your getPublicUrl call: { transform: { width: 800, format: 'webp', quality: 75 } }.

Related Bolt Issues

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