What causes "Why Is Box Upload So Slow?"?

Slow upstream bandwidth (upload is often much slower than download, and Mbps is not MB/s) Third-party firewall, antivirus or VPN inspecting traffic Corporate network restrictions or proxies Box processing each file after upload, noticeable with many small files Intermittent connections breaking large Box Drive transfers

How do I fix "Why Is Box Upload So Slow?"?

1. Check your real upload speed: Run a speed test and look at the upload number Divide Mbps by 8 to get MB/s; a 10 Mbps upload is about 1.25 MB/s 2. Rule out firewall, antivirus and VPN: Temporarily disable third-party firewalls or the VPN and retest Allow Box domains in your firewall if that speeds things up 3. Test another network or a wired connection: Try from home or another location to see whether your office network is the bottleneck Use Ethernet instead of Wi-Fi for large uploads 4. Use the browser for large files: If Box Drive fails or stalls on big files, upload them through box.com Use Folder Upload for many files on unstable connections 5. Try another browser or computer: Update or switch browsers to rule out a browser-specific issue

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Why Is Box Upload So Slow?

Ongoing Web, Windows, macOS Updated October 21, 2026

Quick answer

Box says it doesn't throttle uploads, so slow uploads usually come from your connection's upload speed, a firewall, VPN or proxy, or Box processing many files after upload. Test on another network, disable the firewall or VPN, and upload big batches in the browser.

Most likely fix: Check your real upload speed.

Symptoms

Uploads take far longer than your internet speed suggests, Box Drive uploads appear stalled, or large files fail through Box Drive with network errors but work in the browser.

Why it happens

Slow upstream bandwidth (upload is often much slower than download, and Mbps is not MB/s)
Third-party firewall, antivirus or VPN inspecting traffic
Corporate network restrictions or proxies
Box processing each file after upload, noticeable with many small files
Intermittent connections breaking large Box Drive transfers

How to fix it

Try these in order — the most common fix is first.

1. Check your real upload speed
1. Run a speed test and look at the upload number
2. Divide Mbps by 8 to get MB/s; a 10 Mbps upload is about 1.25 MB/s
2. Rule out firewall, antivirus and VPN
1. Temporarily disable third-party firewalls or the VPN and retest
2. Allow Box domains in your firewall if that speeds things up
3. Test another network or a wired connection
1. Try from home or another location to see whether your office network is the bottleneck
2. Use Ethernet instead of Wi-Fi for large uploads
4. Use the browser for large files
1. If Box Drive fails or stalls on big files, upload them through box.com
2. Use Folder Upload for many files on unstable connections
5. Try another browser or computer
1. Update or switch browsers to rule out a browser-specific issue

This guide also covers

box upload slow
why is box so slow
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Still not working?

If Box keeps failing, you're not alone. See every Box problem users report or the alternatives people switch to.

Why Is Box Upload So Slow?

Quick answer

Symptoms

Why it happens

How to fix it

1. Check your real upload speed

2. Rule out firewall, antivirus and VPN

3. Test another network or a wired connection

4. Use the browser for large files

5. Try another browser or computer

This guide also covers

Still not working?

Other Box errors

Why Is Box Upload So Slow?

Quick answer

Symptoms

Why it happens

How to fix it

1. Check your real upload speed

2. Rule out firewall, antivirus and VPN

3. Test another network or a wired connection

4. Use the browser for large files

5. Try another browser or computer

This guide also covers

Still not working?

Other Box errors