Disk Utility is Apple's go-to macOS app for finding and repairing common disk errors, but if it's your Mac's internal disk that's the problem, then your Mac might not even start up into macOS.

New version of Disk Utility can fix "overlapped extent allocation" errors As noted in Knowledge Base article #25770, the version of Disk Utility (10.5.1) included with Mac OS X 10.4.2 can fixed ...

Repair Disk isn’t the first option you should choose if your Mac is ailing, but it is helpful when (for example): Performance has degraded Data is missing You are experiencing degraded system ...

Macworld At a glance Expert's Rating Pros ・Good level of customization and settings ・Good CPU and RAM usage measurement tools ...