How to see which apps use the most energy on Mac

Start with Activity Monitor’s Energy pane

Open Activity Monitor and select Energy. Energy Impact is Apple’s relative measure of current app energy use. On Mac laptops, 12 hr Power shows average impact over the previous 12 hours or since startup. The pane can also show App Nap and whether an app is preventing sleep.

Energy Impact is useful for comparing apps on the same Mac at the same time. It is not a direct watt reading or an electricity-meter measurement.

Interpret a high reading in context

Compare like with like. A brief export peak and an idle messaging app are different workloads even if they momentarily show similar values.

• Is the app exporting, compiling, indexing, syncing, or playing media?
• Does the reading fall after the task finishes?
• Is an apparently idle app still active in the background?
• Does the same pattern return after restarting the app?

Use KernPulse’s Energy process view

Change the KernPulse process sort mode to Energy. It groups related processes into app-level rows and shows estimated current power in watts plus cumulative energy in watt-hours from the available macOS resource counter.

A live rate needs a change between samples, so the first reading may need another sampling cycle. Grouping is especially useful for multi-process apps such as browsers.

Treat the numbers as diagnostic signals

KernPulse’s values are for relative diagnosis, not billing, laboratory measurement, or battery-health certification. The view may be empty if the required macOS counter is unavailable; KernPulse does not fabricate a substitute.

There is no 24-hour per-app energy history. Long-term history is limited to CPU, overall memory use, and temperature. If an app stays unexpectedly high after its work finishes, save your work, quit it normally, and see whether the pattern returns.