Upload speed explained: why uploading is slower than downloading
Uploading is usually slower than downloading because most internet connections are asymmetric: they are designed to receive far more data than they send. That difference is why a file downloads in minutes but takes an hour to upload.
Why connections are asymmetric
Home and office connections are typically sold with a high download speed and a much lower upload speed, because most people consume more than they publish.
A connection advertised at 100 Mbps down may provide only 10 Mbps up, which means the same file takes ten times longer to send than to receive.
How long an upload takes
These are theoretical figures. Real transfers are slower because of protocol overhead and other traffic on the same line.
| 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 |
| 500 Mbps | About 20 seconds | About 6 minutes |
What slows uploads down
- Wi-Fi instead of a wired connection, especially at distance from the router
- other devices using the same connection at the same time
- video calls, which are particularly sensitive to upload congestion
- VPN connections, which add encryption overhead and routing detours
- background synchronisation from cloud storage clients
- many small files, where each one carries its own overhead
How to make large uploads faster
- Use a wired connection where possible.
- Pause other heavy traffic during the upload.
- Combine many small files into one archive.
- Start large uploads outside working hours if the line is shared.
- Use a paid plan, which includes superior upload and download speed.
FAQ
Why is my upload so slow?
Most connections have far lower upload than download speed. Wi-Fi, VPN, and other traffic on the same line make it worse.
How long does it take to upload 20 GB?
At 10 Mbps roughly five hours, at 100 Mbps roughly half an hour, before accounting for overhead.
Does the transfer service affect upload speed?
It can. Paid plans on MyAirBridge include superior upload and download speed, but the local connection is usually the limiting factor.
Summary
Uploads are slower than downloads because consumer connections are asymmetric by design. Wired connections, avoiding concurrent traffic, archiving many small files, and paid plans with higher speeds are the practical ways to shorten large uploads.