RAMKeeper
Stats vs iStat Menus vs Activity Monitor
Two of these are monitors and one is a diagnostic tool. None of the three will do anything about what it shows you.
These three get compared as if they were competitors. They are not really: one ships with macOS and is meant for investigating a problem, and two live in the menu bar and are meant for noticing one. Which you want depends on which of those you are doing.
The short answer
Install Stats first. It is free, open source under the MIT licence, and as of 11 September 2026 it had 41,711 stars on GitHub with a commit from the previous day. For putting memory, CPU, disk and network in the menu bar, it is as good as the paid options and costs nothing.
Buy iStat Menus if you want more: more sensors, more history, more control over how it all looks. It is the long-standing paid option in this category and it earns its place on depth rather than on doing something Stats cannot.
Keep Activity Monitor for the moment something is actually wrong. It is the only one of the three that shows you per-process detail you can act on, and it is already installed.
What each one is for
| Activity Monitor | Stats | iStat Menus | |
|---|---|---|---|
| Cost | Included with macOS | Free, MIT licence | Paid |
| Lives in | A window you open | The menu bar | The menu bar |
| Per-process memory | Yes, the Memory column | Top processes list | Top processes list |
| Memory pressure graph | Yes, and in the Dock icon | Yes | Yes |
| Sensors beyond memory | CPU, energy, disk, network | CPU, disk, network, sensors, battery | The most of the three |
| Current against peak per app | No | No | No |
| Acts on what it sees | Force quit, by hand | No | No |
The two rows that matter
None of the three shows current against peak. A process sitting at 400 MB that
peaked at 3 GB an hour ago looks identical, in all three, to one that has been at 400 MB all
day. The peak is readable on any Mac with
/usr/bin/footprint -p <pid>, and
it changes what you conclude: in our measured
reading, Docker sat at 0.47 GB with a 2.75 GB peak.
None of the three acts. That is not a criticism, it is their job description: they report. Which is fine until the same application is at the top of the list every afternoon and you are the one quitting it, again.
If you are replacing a cleaner suite with one of these
Sensible move, and worth knowing that a monitor replaces the part of the suite that showed you numbers, not the part that claimed to fix them, because that part was not doing anything. We took that apart with measurements in do Mac memory cleaners actually work, and the job-by-job replacement list is in CleanMyMac alternatives.
Where our own app sits
Openly: RAMKeeper is in the third column that this table does not have, the one marked "acts on what it sees". It attributes memory per app and per browser renderer with current against peak, and it lets you set a ceiling for a specific app and decide once what happens when that ceiling is crossed.
If all you want is to see the numbers, Stats is free and you should use it. The reason to add something else is that watching a number is not the same as doing something about it, and one of those is a chore that repeats.
Disclosure: published by RAMKeeper, which sells a Mac memory tool and therefore competes with two of the three products above. Stats' figures were read from the GitHub API on 11 September 2026. No affiliate links, and no prices are quoted because they change.