Why is my upload so slow?

Uploads are slow mainly because home and office connections provide far less upload than download speed. Wi-Fi, VPN connections, competing traffic, and large numbers of small files make it noticeably worse.

The main cause

Most connections are asymmetric: a line advertised at 100 Mbps download may offer only 10 Mbps upload. Sending is therefore roughly ten times slower than receiving the same file, and that ratio, not the service, sets the pace.

What to check

Cause What to do
Wi-Fi instead of cable Connect by cable for large uploads
VPN active Disconnect it during the transfer if policy allows
Video calls running Wait, calls consume upload bandwidth
Cloud sync in background Pause synchronisation clients
Many small files Combine them into one archive
Shared office line Upload outside peak hours
Old router Restart it, and check the connection speed

Realistic expectations

Real transfers run somewhat slower because of protocol overhead. If your figures are in this range, nothing is wrong.

Upload speed 1 GB 20 GB
10 Mbps About 15 minutes About 5 hours
50 Mbps About 3 minutes About 1 hour
100 Mbps About 1.5 minutes About 30 minutes

When the service is the factor

Paid MyAirBridge plans include superior upload and download speed, which helps when the local connection is not the bottleneck.

If an upload is dramatically slower than your measured line speed and none of the causes above apply, testing on another network is the quickest way to isolate the problem.

FAQ

Why is uploading slower than downloading?

Consumer and business connections are asymmetric by design, with upload speeds often five to ten times lower than download.

Does Wi-Fi slow uploads down?

Yes, especially at distance from the router or on a busy network. A wired connection is more stable for large uploads.

How can I make a large upload faster?

Use a cable, pause other traffic and synchronisation, archive many small files, and upload outside peak hours on shared lines.

Summary

Slow uploads are usually the connection rather than the service, because upload speed is a fraction of download speed on most lines. Cable instead of Wi-Fi, pausing competing traffic, and archiving small files are the changes that actually help.