My MacBook Air from 2019 started feeling like it was underwater. Apps took ten seconds to open. The spinning beach ball showed up three times a day. Safari tabs took forever to load. I started browsing new Macs and immediately closed the browser when I saw the prices.

I spent a Saturday afternoon fixing it with free tools. It is not like new — it is five years old — but it is usable again. Here is what actually helped.

Check What Is Eating Your Resources

Open Activity Monitor — it is in Applications > Utilities. Click the CPU tab and sort by “% CPU.” Look at the top few processes. On my machine, a “helper” process for a photo app I had not opened in months was using 40% CPU. I quit it and the fan stopped whining within seconds.

Also check the Memory tab. If memory pressure is red, you need to close some apps or browser tabs. My Safari had 47 tabs open. Closing 40 of them freed up 2GB of RAM.

Clear the Cruft

System cache and logs build up over time. Empty your Trash. Then in Finder, click Go > Go to Folder, type ~/Library/Caches, and delete the contents of the folders inside. Do not delete the folders themselves, just what is inside them.

Also check ~/Library/Logs — some apps leave multi-gigabyte log files. I found a 3.4GB log file from an old game. Deleted it. Got 3.4GB back instantly.

Login Items Are Silent Killers

Go to System Settings > General > Login Items. Every app that launches at startup slows your boot time and lives in the background using resources. I found 11 items. I kept 3 — the ones I actually need running. The other 8: Spotify, Steam, an old printer utility, several “helper” apps I did not recognize. Removed them all.

Free Up Storage (macOS Needs Breathing Room)

macOS needs at least 10-15% of your drive free for swap files and temporary operations. If your drive is over 85% full, performance tanks. Go to System Settings > General > Storage and see what is eating space.

For me it was old iPhone backups — 28GB worth — and “System Data” which was mostly Time Machine local snapshots. I deleted the old backups and ran tmutil listlocalsnapshots then tmutil deletelocalsnapshots in Terminal. Freed 40GB.

The Nuclear Option That Sometimes Works

Reset NVRAM/PRAM. Shut down. Turn on and immediately hold Option-Command-P-R for about 20 seconds. Your Mac will restart. It clears some low-level settings that can cause weird performance issues. Safe, free, and occasionally fixes things that nothing else touches.