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.

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. 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 Luca Liberati Luca Liberati I work on monoliths and microservices, backends and frontends, manage K8s clusters and love to design apps architecture 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) 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. Pratik Pratik SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure 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. 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. Tejas Chokhawala Tejas Chokhawala Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript. Focused on performance, clean architecture and shipping fast. Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools.

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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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