Sync and cloud storage

What is Dropbox?

The Dropbox desktop app syncs the files in your Dropbox folder. Its traffic is your files going up and down, plus LAN sync, which talks to other Dropbox computers on the same network.

Process: DropboxAlso seen as: DropboxMacUpdate, Dropbox Web HelperMade by DropboxApplies to: The Dropbox desktop app on macOS 14 Sonoma and later. Checked on 1 November 2026 against Dropbox's help centre.Checked: 1 November 2026

Short answer

The Dropbox desktop app. It uploads and downloads your Dropbox files, and with LAN sync it finds other Dropbox computers on the local network.

Block with care

Blocking it stops Dropbox sync on this Mac. Your files stay, but changes don't reach other devices. Pause sync instead.

Path
/Applications/Dropbox.app/Contents/MacOS/Dropbox
Signing identifier
com.getdropbox.dropbox

What it is

Dropbox's firewall article names three processes on a Mac. “Dropbox” is the app, “DropboxMacUpdate” updates it and “Dropbox Web Helper” is its web helper.

Dropbox says that the desktop app needs ports 80 and 443. To open files in other apps, it also needs ports 17600 and 17603.

Dropbox's LAN sync article says that clients find each other with UDP broadcasts on port 17500. They then transfer files directly over HTTPS on a TCP port between 17599 and 17609.

Why it uses the network

  • File sync. Files that you add or change upload, and changes made elsewhere download.
  • LAN sync. Dropbox says that LAN sync broadcasts which accounts and shared folders a computer has, without private details. Other computers then copy files directly.
  • Updates. DropboxMacUpdate downloads and installs new versions of the app.

How much is normal

Bursts after you change files are usual. The amount is about the size of the files.

With LAN sync on, small broadcasts on the local network every so often are expected. Dropbox says that they go out at a regular interval.

Dropbox says that LAN sync uses IPv4 only.

When it uses a lot, and why

  • A big folder added. Moving a large folder into Dropbox uploads all of it. That can take hours on a slow upload.
  • A new computer. Signing in on a new Mac downloads every file that this Mac keeps locally.
  • LAN sync overriding limits. Dropbox says that turning on LAN sync overrides your bandwidth settings on a LAN, which may speed up syncing there.

Is it safe to block?

Block with care

Blocking it stops Dropbox sync on this Mac. Your files stay, but changes don't reach other devices. Pause sync instead.

What breaks if you block it

  • Files don't upload or download, so this Mac and your other devices drift apart.
  • Shared folders stop updating for you.
  • Updates to the Dropbox app can't download, and LAN sync stops.

Blocking means a firewall rule that refuses its connections. Don’t quit or disable a macOS process to save data: macOS starts it again, and other features depend on it.

Reduce its use

  1. To pause, click the Dropbox icon in the menu bar. Click the sync status at the bottom of the window.

  2. Choose 30 minutes, 1 hour, Until tomorrow or Indefinitely. Dropbox says that changes then don't update in the Dropbox folder.

  3. Dropbox says that you can't pause from dropbox.com or the mobile app.

  4. To turn LAN sync off, open the Dropbox app's Preferences from the account menu, then change the LAN sync setting.

See how much it uses

  1. Open Activity Monitor from Applications › Utilities. Click Network.

  2. Type Dropbox in the search field. The Sent Bytes and Rcvd Bytes columns show what it moved since it started.

  3. In Terminal, watch only this process. Press d to show the change per second, and q to quit.

    nettop -p 'Dropbox' -P

With Kilobat

  1. Kilobat counts Dropbox as a sync app. Call mode and Send later can hold it while you are on a call or a slow link.

  2. In the Kilobat app list, search for Dropbox. Its row shows the live rate and what it moved today.

  3. Ask the same question in Terminal.

    kilobat explain Dropbox

  4. Show its traffic over one day.

    kilobat bandwidth Dropbox day

The live view and the explanations are free. History in the app needs Kilobat Pro. Blocking needs Pro and the network filter: see the network filter, Protection and the hotspot data saver.

Hosts it contacts

Apple and the maker document these hosts for this feature. A process can also contact others; Kilobat’s Connections tab shows what it actually opens on your Mac.

dropbox.comDropbox's official domains for its product, API and static content.Dropbox →*.dropboxusercontent.comA Dropbox domain on its list of verified domains, with hosts such as dl.dropboxusercontent.com.Dropbox →

Questions

Does LAN sync send my files to strangers on the network?

Dropbox says that LAN sync is subject to the same access controls as its servers. Only computers with access to a folder get its files.

Why does Dropbox upload when I didn't change anything?

Another app may save into the Dropbox folder, or a shared folder changed. The Dropbox menu shows what is syncing.

Sources

Checked on 1 November 2026.