is mac cleaner safe to download

NO.

Do not install any such software on your premium quality Macintosh computer. It is already well protected and does not accumulate filth.

Everything needed to keep it in top running condition was included in the box it shipped in, except one: an external drive on which to store your backups. The Time Machine software to make the backups, quietly in the background, was also included.

No, **** no.

Not even slightly.

In case there is any doubt, let me also add my negative response here. NO.

Any software claiming to clean, increase security, improve performance or protect you from virus is a scam and should be avoided.

If you have a problem please state what it is.

Excerpted from Effective defenses against malware and other threats:

Never install any product that claims to "clean up", "speed up", "optimize", "boost" or "accelerate" your Mac; to "wash" it, "tune" it, or to make it "shiny". Those claims are absurd.

• Such products are very aggressively marketed. They are all scams.
• They generally operate on the flawed premise that a Mac accumulates "junk" that needs to be routinely "cleaned out" for optimum performance.
• Trial versions of those programs are successful because they provide the instant gratification of greater free disk space.
• That increased space is the result of irreversible destruction of files, programs, or operating system components normally protected from inadvertent alteration or deletion. The eventual result will be unreliable operation, poor performance and random crashes that may not become evident for months or even years after their use, when updates to programs or OS X are eventually released.
• Memory "cleaners" that circumvent OS X's memory management algorithms work by purging inactive memory contents to mass storage, which can only result in degraded performance and accelerated hardware failure.

In other words, no.

NO NO NO!!  😮 and if that wasn't clear DO NOT install third party defense or cleaners (mackeeper, clean my mac, macdefender etc.) for mac!!!!!! they will delete memory that is sometimes dormant but vital to the storage operating system. that means corrupted files and crashing programs that before worked fine and if you don't do a clean OS reinstall quickly you'll have hardware failures of the hard drive. all files gone if you don't have external hard drive for using Time Machine for backups. now do think it's ok to pay for that cleaner?

And don't install Sierra on a 2010 macbook pro. the farthest I think you should be is Yosemite unless you know what you're doing or have someone who does.

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