Find the process using the most RAM on Mac

Memory pressure is climbing, you can hear the SSD working overtime as macOS swaps, and you’d like to know which app to close before everything grinds. The good news is that pinpointing the worst memory user takes about ten seconds — once you know where to look.

Three ways to find it

Activity Monitor

Still the canonical way.

1. Open Activity Monitor (Spotlight: Activity).
2. Click the Memory tab.
3. Click the Memory column header to sort descending — biggest first.
4. Check the Memory Pressure graph at the bottom. Green is fine, yellow is borderline, red means you're paging to disk.

The number to look at is Memory (real memory footprint), not “Real Memory Size” or compressed memory — Apple consolidated that. The top entry is your hog.

Terminal: ps and top

When you don’t want to open another GUI:

ps -axm -o rss,pid,comm | sort -nr | head -10

That prints the top ten processes by resident set size (RSS) in kilobytes. Divide by 1024 for MB.

Or use top:

top -o mem -stats pid,command,mem

The -o mem sorts by memory, -stats trims the columns to what you care about. Quit with q.

A menu bar monitor

If you find yourself doing this often, a menu-bar readout removes the “where do I look” step entirely. Beacon shows live memory pressure in the bar, and clicking the readout drops a panel with the top RAM users — no app switching.

1. Install Beacon and enable Memory in Settings > Menu Bar.
2. Pick percentage, pressure colour dot, or a small graph.
3. Click the readout — top three memory users appear instantly. Click one to open Activity Monitor scoped to it.

What counts as “too much”

Modern macOS aggressively uses free RAM as cache, so a Mac at “95% used” can be totally fine. The number that matters is memory pressure:

• Green — plenty of headroom, ignore the gigabyte numbers.
• Yellow — compressed memory is being used heavily, mild concern.
• Red — you’re paging to disk, every app feels slow, this is when to close something.

The usual suspects in 2026 are browsers (especially with many tabs and extensions), Electron apps (Slack, VS Code, Notion, Figma desktop), and creative apps holding large project files in memory. If you see one of those at several gigabytes and you’re not actively using it, quit it — you’ll feel the relief immediately.