This question comes up almost every week. Someone has a dozen apps open in their Dock, their Mac feels slower than it used to, and they want to know whether quitting everything at the end of the day would help. Usually the answer is: not much. Sometimes the answer is: yes, but only one specific app.
Shiny is a small menu-bar tool for keeping an eye on memory pressure, so a lot of attention has gone into how macOS actually handles apps in the background. The "quit everything" habit is mostly Windows-era thinking applied to Mac, and it does not match how macOS actually works. The more useful question is: which apps are genuinely doing something in the background, and which ones are just sitting there?
This post is the bigger-picture companion to does closing apps free RAM on Mac, which focuses on what happens to memory when you quit. Here I want to answer the broader habit question: as a general practice, should you quit apps or leave them open?
Does leaving apps open hurt your Mac?
For most apps, no. macOS has a built-in memory management system that handles inactive apps quite gracefully. When you stop using an app and switch to something else, macOS gradually compresses that app's memory footprint. If the system needs more RAM, it can reclaim some of what that idle app is holding. From the user's perspective, the app is still open. From the system's perspective, it's been quietly put in a box.
This is why having 12 apps open on Mac is not the same as running 12 apps simultaneously. Most of them are just parked. The ones actually doing work are the ones in the foreground and any apps running background tasks.
The myth that open apps always consume full resources comes from Windows, where application memory management has historically been more manual. On Mac, Apple has spent years building an OS that manages this automatically. Trusting it is usually the right call.
The number to watch if you're ever unsure is the Memory Pressure graph in Activity Monitor, not "Memory Used". What memory pressure actually means on Mac is covered in a dedicated post, but the short version is: green means your Mac is coping fine, regardless of how many apps are open. Yellow or red means something is actively competing for RAM, and that's when it's worth investigating.
The exceptions worth quitting
That said, some apps genuinely keep working in the background whether you're using them or not. These are the ones worth being deliberate about.
Cloud storage clients. Dropbox, Google Drive, OneDrive, and iCloud Drive are all actively syncing whenever your Mac is awake. They watch for file changes, upload new versions, and check for updates from other devices. If you're not actively using cloud sync and you're on a slow connection or trying to preserve battery, quitting the sync client is a real win. Leaving it open is also fine if you want it doing its job quietly in the background; just know that it is actually doing something.
Apps with background update and scan processes. Adobe Creative Cloud is the most common example. It installs a background helper that checks for updates, even when you haven't opened Photoshop or Illustrator in days. Similarly, some photo backup apps (Google Photos, Amazon Photos) scan your library and upload in the background. These apps can consume meaningful CPU and network bandwidth without you realizing it. Quitting them when you're not actively using their core features is a reasonable habit.
Apps that have developed a memory leak. This is rarer, but real. Some apps gradually consume more and more RAM the longer they run, even when they're just sitting idle. Chrome, Slack, and Microsoft Teams are the most commonly cited examples, though this tends to vary by version and by how heavily you use them. If your Mac reliably slows down over the course of a day and feels fine again after a restart, one of your long-running apps is the likely cause. Sorting the app list in Activity Monitor by Memory will usually reveal the culprit quickly.
The honest "leave them open" case
For everything outside those three categories, keeping apps open is genuinely fine. Browsers (when you're not running 40 tabs), text editors, music apps, note-taking tools, chat apps when they're not in active use: these sit in the background and cost very little.
There's also a practical cost to quitting everything. Apps take time to relaunch. Your session state, your open windows, your scroll position: these reset. For apps you switch between regularly throughout the day, the overhead of closing and reopening adds up in ways that quitting every app simply doesn't justify.
The people who benefit most from habitually quitting apps are those running Macs with 8 GB of RAM who regularly use several heavy apps at once. If you're running a video editor, a browser with 20 tabs, and a design tool simultaneously on 8 GB, you will hit genuine memory pressure. In that situation, being deliberate about what's open makes a real difference. If you're on 16 GB or more and your usage is moderate, you can safely leave almost everything open and let macOS do its job.
Apple's own documentation on checking whether your Mac needs more RAM is worth reading if you want to know whether your hardware is genuinely the limiting factor.
When to quit, when to restart
Rather than a daily app-quitting ritual, these are the moments when quitting (or restarting) actually makes a difference.
When Memory Pressure goes yellow or red. This is the clearest signal that something is genuinely competing for RAM. Open Activity Monitor, sort by Memory, and find the biggest consumer. Quit that specific app. You'll likely see pressure ease back toward green within a minute. This is a targeted response to an actual problem, rather than a precautionary habit.
When you notice a specific app misbehaving. If an app is lagging, showing stale data, or feeling noticeably slow, quitting and relaunching it is the right move. A fresh relaunch clears any accumulated state and is often faster than troubleshooting the symptom.
At the end of the day if you're restarting anyway. If you restart your Mac most evenings, apps quitting is handled automatically. You don't need to do it manually beforehand.
Restarting weekly is a better habit than quitting individual apps daily. A weekly restart clears compressed memory, resets apps that have been running continuously, and gives macOS a fresh start. It costs you about a minute and pays off more reliably than quitting individual apps throughout the day. If you're doing one thing differently after reading this, make it a weekly restart rather than a daily quit-everything session.
If you find yourself watching Memory Pressure often and wish something could handle it more quietly, that's the gap Shiny fills. It shows you pressure at a glance from your menu bar and frees memory in one click when things get tight. If you're trying to decide whether a tool like that is worth it, the post on whether Mac cleaner apps are actually worth it covers how to think about the whole category honestly.
Bottom line
For most apps on Mac, leave them open. macOS compresses and parks inactive apps so they cost almost nothing. Quitting them doesn't free as much as people expect, and relaunching them adds friction without a proportional benefit.
The apps worth being deliberate about are cloud sync clients (Dropbox, Google Drive), background scanner apps (Adobe Creative Cloud, photo backup tools), and anything you know has a memory leak. Those are actually doing work, and quitting them when you don't need them is a reasonable choice.
The right signal is always Memory Pressure, not Memory Used, and not the number of icons in your Dock. Green pressure with 15 apps open is a healthier Mac than red pressure with 3 apps open. Let the graph guide you rather than a fixed habit either way.