Why Is Dropbox So Slow?
If Dropbox is syncing slowly, this could mean that you need to change its bandwidth settings. By default it's set to run in the background and use minimal amounts of your bandwidth. It could also mean that your Internet connection is suffering temporary issues, or that there's some interference with your computer's security software. You can fix most speed-related issues by troubleshooting your connection and the app and making sure your app is up-to-date.
1 Dropbox Bandwidth Limited
By default, Dropbox throttles its own upload speed so that it doesn't interfere with your Internet connection. It limits itself to roughly 75 percent of your total upload speed, whereas downloads are unlimited by default. You can adjust both upload and download bandwidth limitations from Dropbox's settings. Click on Dropbox's icon in your task bar, and then click the gear icon and "Preferences." Click "Bandwidth," and then select "Don't limit" under the download and upload rates. Click "OK" when you're finished.
2 Internet Connection Problems
If your Internet connection is experiencing problems overall, this will affect how quickly Dropbox can operate, even if its set not to throttle itself. This can happen if you have a slow connection, temporary connection issues or if you're connected wirelessly and have poor or unstable signal strength. Restarting your router will correct many temporary Internet issues. If you're using a wireless device, make sure you're close enough to the router that you receive a stable, strong signal.
3 Firewall and Anti-Virus Protection
As a program that does a lot of uploading and downloading, especially between computers on your own network, you may have some trouble with certain firewall or anti-virus applications. If Dropbox is experiencing problems and your other applications are working fine, open your security software and add Dropbox to your whitelist. Many firewalls require specific permission from you before programs are allowed to access the Internet, so make sure Dropbox is allowed to run.
If your Internet is working fine and all your programs except Dropbox are working fine, try restarting the Dropbox app itself to correct any temporary errors. You can also test to see whether the problem is with Dropbox servers or with your app by accessing your Dropbox dashboard via your Web browser. Update to the latest version of the Dropbox app on your computers and mobile devices, since updates often contain bug fixes and improvements.