Large File Downloads Timing Out in Lovable App
Users trying to download large files (PDFs, exports, media) from your Lovable app experience timeouts, incomplete downloads, or connection resets. The download starts but never completes, or fails with a network error.
This commonly happens with generated reports, data exports, or media files that exceed a few megabytes. The download may work fine for small files but consistently fail for anything larger.
The problem is worse on mobile connections and may appear as a spinning indicator that never completes or a partially downloaded corrupt file.
Error Messages You Might See
Common Causes
- Serverless function timeout — Edge functions have execution time limits (typically 10-30 seconds) that large downloads exceed
- File loaded into memory — The entire file is read into memory before sending, instead of being streamed
- No resume support — If the connection drops, the download must restart from the beginning
- CORS on storage URLs — Direct storage URLs may not have proper CORS headers for browser downloads
How to Fix It
- Use signed URLs for direct download — Generate a temporary signed URL from Supabase Storage and redirect users to it instead of proxying the file
- Stream large files — If you must process the file, use streaming instead of loading it entirely into memory
- Add download progress indicators — Show users how much has been downloaded so they know the download is working
- Set appropriate timeouts — Increase function timeouts for download endpoints, or bypass serverless functions entirely
Real developers can help you.
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.
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ISHANTDEEP SINGH
Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems.
Kingsley Omage
Fullstack software engineer passionate about AI Agents, blockchain, LLMs.
Pratik
SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure
Nam Tran
10 years as fullstack developer
Matt Butler
Software Engineer @ AWS
Bastien Labelle
Full stack dev w/ 20+ years of experience
Antriksh Narang
5 years+ Experienced Dev (Specially in Web Development), can help in python, javascript, react, next.js and full stack web dev technologies.
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.
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.
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
What's the maximum file size I can serve?
There's no hard limit on file size in Supabase Storage, but serverless functions typically have a 50MB response body limit and 10-30 second execution limits. Use signed URLs for files larger than a few MB.
Why do downloads work on WiFi but not mobile?
Mobile connections are slower and more prone to disconnections. Without resume support, a brief connection drop means the entire download fails and must restart.