When you upload multiple files in the web app, they aren’t all sent at the same time. To keep performance smooth and prevent overload in your browser and on our servers, the system uses a queued upload process with a small number of files uploading simultaneously.
This works very reliably on strong, stable internet connections, but can run into issues on slower or unstable networks.
Below is a high-level look at how uploads work and why failures are more likely in certain conditions.
How multi-file uploads work
When you select several files to upload:
All selected files are added to an upload queue
Up to five files upload at the same time
Each file uploads in small pieces (chunks)
As soon as one file finishes, the next file in the queue starts automatically
This approach helps:
✅ Keep uploads fast
✅ Avoid browser slowdowns or crashes
✅ Maintain reliable performance for all users
What happens when a file runs into network issues
Each file is uploaded in many small chunks.
If a chunk fails due to a weak or unstable connection, the system automatically retries the upload using a backoff retry process:
The first retry happens quickly
Each additional retry waits longer than the previous one
Up to five total attempts are made per file
If all retry attempts fail, that file’s upload stops.
This prevents endless retries while still giving the network time to recover.
Why slower connections are more likely to fail
On unstable or low-bandwidth networks (such as poor mobile reception):
Chunk uploads fail more often
Retries take longer and longer
A slow file occupies one of the five upload slots for an extended time
When this happens:
⏳ The queue moves very slowly
❌ Some files may never complete
📉 Upload failures become more likely
Why strong Wi-Fi works much better
On fast, stable connections:
Chunks upload quickly
Files finish without retries
The queue continues smoothly
This is why users often succeed uploading many files on Wi-Fi but see failures when network quality drops.
Other factors that can affect large uploads
When uploading many files at once, a few additional limits may come into play:
Browser connection limits
Temporary server protections against rapid requests
Device performance constraints (especially on mobile devices)
These are normal safeguards used across modern web apps.
Best practices for reliable uploads
For the most consistent results:
✅ Use a strong Wi-Fi connection when possible
✅ Upload in smaller batches (5–8 files at a time works best)
✅ Let one batch finish before starting another
✅ Avoid switching networks during uploads
Summary
File uploads use a queued system where up to five files upload at the same time.
Each file automatically retries up to five times if network issues occur.
On strong connections this works smoothly.
On slower or unstable networks, retries and delays can cause uploads to fail — especially when many files are selected at once.
Uploading in smaller batches on a stable connection is the most reliable approach.