my Mac is very sluggish

Hi. Is it an old mac? It sounds like you might have a ton of junk files on there. Things like files from uninstalled programs, safari extentions you don't need etc. You'll want to at least see how your hard drive works, then see if you can purchase a program that will help. clean my mac, is a great one. Once bought, you just need to prsh a few keys, wait awhile, then let it clean. You can not mess up your mac, it's foolproof.

If your Mac is running slowly, the first thing to try is to restart it. If that doesn't work, check how much free space you have available on your startup disk. If it is almost full, you may want to delete or move files you don't use to another location to save space.

If you want the computer to automatically move older files into iCloud and you have enough iCloud storage to do so, choose Apple>about this Mac and select storage in the toolbar. Select the manage button next to your startup disk, and in the resulting list of recommendations, there should be a, "Store in iCloud," button. This will store files which you haven't opened recently in your iCloud Drive and download them to your Mac when you need them. That list should also give options to delete already watched iTunes movies and tv shows and to review large files for deleting.

Another thing to check is how much of the CPU and ram you're using. Quit any applications and close any windows you're not using and open Activity Monitor, located in the Utilities folder. Make sure CPU and ram usage is low, and quit any processes you're not using from the table.

You can also manually clear the caches that are stored in the various library folders. Caution: only delete the files in these folders, not the folders themselves. Also, do not delete anything in the library folders unless you are certain what it is. To clear your user cache, press Command Shift G in the Finder and type ~/library. Open the, "Caches," folder and press Command A to select all. Press Command delete to move them to the trash and exit the now empty folder. While in this location, you can also clear your log files by opening the, "Logs," folder and moving all those files to the trash. To clear your system cache, open your startup disk, usually called Macintosh HD, and go to the library folder. Repeat the process for the, "Caches," and, "Logs," folders. You can also do this in the library folder in the system folder at the root of your startup disk. In these locations, you may be prompted for an administrator password, as these files aren't owned by any particular user account.

Finally, if your browser is running slowly, you can clear its history, cookies, and downloads. In Safari, to clear history, choose Safari>clear history and choose how much of it you want to clear. To clear cookies, choose Safari>preferences and click privacy. Click manage website data, and in the resulting window, you can choose to remove individual cookies, or remove all. Note: you will be signed out of any websites you were previously signed into. To clear downloads, choose view>show downloads and click clear.

HTH

Try a clean install. Save all important files like documents and then perform a clean install of OS X. Don't restorefrom any backups. Configure all your applications from scratch and copy your important data from your backup you saved earlier. That should resolve the sluggishness. I always perform clean installs. It's a good idea to do this periodically to clean out old junk and get a squeaky clean system. Another great time to do this is when new versions of the OS are released to the public.

I know you said you bought it in 2015, but this may be a suggestion. If all else fails, I'd be inclined to believe it's a hard drive issue. Maybe some part(s( got loose or maybe it's worn out & about to die. That does happen. In that case, backup your data NOW, & see if you can get a repair.

I also have a question about what kind of hard drive it is. Is it a Spinning Drive? Or it it a Solid-state Drive or SSD? If it's an SSD., then I have some more recommendations. However, I will caution you on these. My only cautionary advice would be to do these only every once in a while. Because you could actually damage your SSD., or you may even shorten its lifespan. Now, with that said, if all else fails, I'd try this. You can try running a defrag. This is the main one I'd caution you about.

However, you could try running TRIM. For the most part, SSD. drives do garbage collection on there own. Sometimes, it's not done, due to a number of reasons such as a but in the OS. This happened with Android at one point for example. But this process of garbage coblection is called TRIM.

Also, SSD.'S do slow down over time so it may be that it's just getting slow.

This may or may not fix your problems, but from what I'm reading & my understanding, it sounds to me like it has something to do with your hard drive. Hope this hebfs, & good luck!

If anyone owns any kind of ssd, do not defrag it,ever. its a bad bad idea. like, really bad!

People should really take more care before they throw out suggestions like that out there.

OP, did el capitain work fine on your macbook air?
Its probably slow because sierra is a bit too much for it,but like others have said it could also be caused due to hdd issues or junk files.

T dog and cris, good suggestions, although a clean install isn't likely to help if the macbook air 11.inch can't just handle the OS.

Hello,
You may have already done this but, Sierra did a few things by default that I always check after an install or update. The symptoms you describe could be syncing sluggishness. I have found it really pays to go to iCloud settings and check everything that is being synced.
The first thing I turn off is 'Desktop and Documents' in the iCloud Drive Settings. When left on, this option will continually try to upload/sync your entire desktop and the Documents folder to iCloud Drive. A very handy option if you have a very fast computer and wifi, and if you actually want all that available for your other devices. However, many people have stuff being synced to iCloud, without realizing, since much of this is synced by default. Other than backing up to the cloud, in most cases syncing should be used for sharing data between devices, depending on your own personal setup.

Go to, System preferences/iCloud/iCloud services Group/iCloud Services Table, and uncheck the items that you don't want syncing.

Then interact with iCloud Drive row and click the 'Options' button, and go to,
Options Button/documents Tab/Applications Table/

In the 'Applications Table', I uncheck 'Desktop and Documents Folders'.
Then below the table I uncheck 'Optimize Mac Storage', which is, "The full contents of iCloud Drive will be stored on this Mac if you have enough space. Older Documents will be stored only in iCloud when space is needed.".
Possibly a neat option that I don't currently use. The space is not the concern, it's the processing/bandwidth/disk buffering that slows the system. When finished, click the 'Done' button to leave the window.

Another sluggish spot can be in System Preferences/Energy Saver/Power Adapter tab.
I may get some finger wagging for this, but I set all levels to occur 'Never'. I do not let the hard drive sleep. This is only for power adapter mode. My screen brightness is set to 0 all the time. I leave the Battery tab settings set to default. Most of the time my Mac is plugged in, while in use. If I wish to engage the default settings for a time, I unplug the power and let it switch to Battery.
I should note the Mac has an old spinning disk still, not sure how much this applies to a SSD.
I guess the main idea is, it pays to spend some time in System Preferences and know how your Mac is currently set. There can be many sluggish spots that can be cleared up by unchecking a box or two. You can always back out of areas without changing anything if needed. After you change things and are done, it is always best to restart once, so you are running on the new settings.
Sometimes the easy fixes really work. :-)
My apologies if you have already tried this route. Best of luck for you!

As mentioned by other commenters, persistent sluggishness may be caused by a problem with your internal disk. You can check its status by running first aid in Disk Utility, located in the Utilities folder.

By default, there should be two disks in the table, something like, "Apple SSD," and your startup disk, usually called Macintosh HD. Other disks and volumes will appear if you have external storage connected to your Mac or other partitions on your internal disk. I'd recommend running first aid on the root, something like, "Apple SSD," to check the disk structure and partition map, and your startup disk, to verify the integrity of the MacOS file system.

HTH

Hi,
Here are a few programs aside from Clean My Mac3, and Gemini2.
There is CCleaner,, Monolingual which removes that unused languages that people don't speak. So this can help if you only speak one language. The last program is App Cleaner, but this one I would recommend you have a sighted person help you with, because it has a pop up for every application. So trying to navigate the table to find said app/apps to uninstall gets kind of difficult.
These are for the most part VoiceOver friendly. There are a couple of unlabeled buttons. but to my knowledge the ones that are needed to do the job the software does. are labeled.