Apps Slow to Open on Mac? Causes & Fixes

A Mac that's fine once you're working but takes fifteen seconds to open anything has a launch problem, not a performance problem — and they have different causes. The useful question isn't “is my Mac slow”, it's “is it slow every time, or only the first time?” That one distinction narrows it to two or three possibilities.

Only the first launch is slow

If an app crawls the first time you open it after installing or updating, and is fast every time after, nothing is wrong. Three things happen exactly once:

• Gatekeeper verification. The first time you launch a downloaded app, macOS checks its signature and notarisation and scans it. For a large app this can take several seconds — you'll see syspolicyd busy in Activity Monitor. It doesn't repeat. See how Gatekeeper works.
• Rosetta translation. On Apple silicon, opening an Intel-only app translates its code before it runs. That's a one-time cost per app version, and the app is noticeably slower after that too — check About This Mac → More Info → System Report → Applications to see which of yours are still Intel.
• First run after a macOS update. Caches are rebuilt across the board; see what's normal after an update.

Every launch is slow

This is the case worth investigating. Work down the list — they're ordered by how often they turn out to be the answer.

1. The startup disk is nearly full

Launching an app means reading a lot of small files. When the drive is close to full, macOS is short of room for swap and cache and every read gets slower. Check System Settings → General → Storage — if you're below about 10% free, fix that first and re-test before touching anything else. What to do when the disk is almost full.

# Free space on the data volume
df -h /System/Volumes/Data

2. You're already out of memory

If memory pressure is yellow or red, launching anything means macOS has to swap something else out to make room. Open Activity Monitor → Memory and check the pressure graph before launching — if it's not green, the launch delay is a symptom, not the disease. Reading memory pressure.

3. The app lives in iCloud Drive or on a network volume

An app stored in iCloud Drive or on an external or network disk has to be fetched before it can run. Apps belong in /Applications on the local disk — if yours are in Documents or Desktop with iCloud Drive syncing those folders, move them. The cloud icons in Finder tell you what's local and what isn't, and this guide covers forcing files back down.

The same applies to documents: an app that opens instantly with a blank window but takes thirty seconds to restore your last file is waiting on the file, not on itself.

4. Everything is launching at once

Right after login, a dozen background helpers are starting and Spotlight may be indexing. Anything you open in the first two minutes competes with all of it. If launches are only slow early on, the fix is the login list rather than the app: System Settings → General → Login Items (Login Items & Extensions on macOS 15 Sequoia and later), then work through managing startup items and slow boot.

5. Spotlight is stuck indexing

Indexing is normally invisible. If mds_stores or mdworker has been busy for days, the index is probably corrupt and reindexing forever.

# Is indexing enabled and finished? (read-only)
mdutil -s /

If it never completes, rebuild the index — it's slow for a few hours and then permanently better.

6. Something is scanning every file you open

Third-party antivirus and some backup or sync tools hook into file access, which adds a delay to every launch. If you installed one recently and launches got slower at the same time, that's your answer. macOS already includes Gatekeeper, XProtect and notarisation checks; for most people, a third-party scanner costs more performance than it adds safety.

When it's one specific app

If everything else opens instantly and one app doesn't, it's the app, not the Mac. In order:

1. Check for an update. Slow launch after a macOS upgrade is often an app that hasn't caught up.
2. Look at what it opens with. Editors and browsers restoring dozens of tabs or documents are slow by choice — start them with a blank session and see.
3. Reset its preferences. A corrupt preference file makes some apps hang at launch. Quit the app, move its .plist out of ~/Library/Preferences to the Desktop, and relaunch; if that fixes it, delete the old file. If not, put it back.
4. Reinstall properly. Dragging to Trash leaves support files behind — remove the leftovers first, then reinstall.

The settings-level fixes above are one-click, reversible toggles in Mainspring — labelled in plain English, with an undo button for every one.

Common questions

Why is an app slow to open the first time only?

macOS verifies a downloaded app's signature and notarisation on first launch, and on Apple silicon it also translates Intel-only apps through Rosetta. Both are one-time costs per app version, so later launches are fast.

Does low disk space make apps slower to launch?

Yes. Launching reads many small files, and a nearly full startup disk leaves macOS short of room for swap and caching. Below about 10 percent free, launch times get noticeably worse.

Why do apps open slowly right after I log in?

Login items, background helpers and Spotlight indexing all compete for CPU and disk in the first couple of minutes. Trimming the Login Items list, especially the Allow in the Background section, is the fix.

Should I install antivirus on a Mac?

For most people, no. macOS includes Gatekeeper, notarisation checks and XProtect. Third-party scanners hook into file access, which slows down every app launch and file operation.

How do I know if an app is Intel or Apple silicon?

Open About This Mac, then More Info, System Report, and select Applications. The Kind column shows Universal, Apple Silicon, or Intel for every installed app.