Whether you’re troubleshooting network issues or just trying to save bandwidth, it’s useful to keep an eye on your Mac’s network usage over time. With Activity Monitor, Apple makes it easy to monitor network activity at a glance in the Dock. Here’s how to set it up.
First, open “Activity Monitor”. If you aren’t sure how, you can do it quickly using Spotlight. Press Command + Space or click the “magnifying glass” icon on your menu bar, and a search bar will appear. Type in “activity monitor”, and press Return.
Next, right-click the Activity Monitor Dock icon. In the menu that appears, click “Dock Icon”, then select “Show Network Usage”.
Once “Show Network Usage” is selected, the Activity Monitor dock icon will change to an animated display depicting network activity over time, updating from right to left.
(By default, this graph is updated every 5 seconds. If you want to change the rate at which the graph updates, visit View> Update Frequency on the menu bar at the top of the screen.)
Under the default settings, the network usage Dock graph shows “packets per second,” in blue and “packets out per second” in red. This is the raw amount of data packets received and sent from your Mac.
If you prefer a different read, you can have the graph display the data sent and received in bytes. First, click the main Activity Monitor window (press Command + 1 to make it appear if it’s not already open), and select the “Network” tab.
Find the small graph at the bottom of the window. Click the header that says “Package”, and change it to “Data” using a small drop-down menu.
Once “Data” is selected, the Dock chart will change immediately. Now “data reads per second” is shown in blue, and “data bytes written per second” is shown in red.
When you have the Dock icon configured the way you want it, feel free to close the main Activity Monitor window by pressing the red “X” button.
With the main window closed, Activity Monitor runs quietly while you perform other tasks on your Mac, and the network usage graph in the Dock is constantly updated. If you close Activity Monitor, the Dock icon will change back to normal.
If you want to change the Activity Monitor icon back to normal while it’s running, right-click the Activity Monitor Dock icon again and select “Dock Icon”> “Show Application Icons”.
When you’re done, it doesn’t hurt to have another look at Activity Monitor and explore other options. You will see that it has many useful tricks.