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.
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.
Matt Butler
Software Engineer @ AWS
Victor Denisov
Developer
Jaime Orts-Caroff
I'm a Senior Android developer, currently working at Aircall. I'm open to work in various fields!
legrab
I'll fill this later
Simon A.
I'm a backend developer building APIs, emulators, and interactive game systems. Professionally, I've developed Java/Spring reporting solutions, managed relational and NoSQL databases, and implemented CI/CD workflows.
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.
Pratik
SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure
Bastien Labelle
Full stack dev w/ 20+ years of experience
MFox
Full-stack professional senior engineer (15+years). Extensive experience in software development, qa, and IP networking.
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.