GlimmerStatsBarSee what is moving across your connection.
A nearby traffic reading can give a download, call or sync a little context.
Watch current upload and download rates
GlimmerStatsBar (mac stats bar) displays bytes per second for one public default-route interface. That keeps the overview focused on the route your Mac is currently using. It does not add a VPN interface and its physical transport together.
Look at recent traffic
Open Network to explore traffic on a world map, sort apps and locations by upload or download, and look at connection details. Optional per-app traffic needs macOS approval. Choose a 5, 15 or 60-minute history view.
A network monitor and a speed test do different jobs
A monitor watches the traffic that is already moving. A speed test creates transfers to estimate available throughput to a test service. GlimmerStatsBar (mac stats bar) does not run speed tests or guarantee the quality of an internet connection.
A changed route needs a new baseline
Switching networks, connecting a VPN, sleep, counter resets or long sampling gaps can interrupt a rate reading. The app starts a fresh baseline rather than treating the change as a burst of traffic. Check the interface name in the live card when a reading looks unexpected.
Read more from Apple
Questions you might have
Does this show my internet plan speed?
It shows observed upload and download traffic, in bytes per second, on the current default-route interface. It is not an internet speed test or a measurement of the maximum speed in your plan.
Why is network usage temporarily blank?
The app needs a fresh interval to calculate a rate. A route change, counter reset, sleep or a longer gap can require a new baseline.