There are so many things that everyone needs to worry about in life, but we believe that data loss shouldn't be one of them. Still, the novel sitting on your Mac or the family photos that weren't downloaded from a digital camera and printed as part of a photo book all require a storage medium to keep onto them until they finally materialize as a printed book or framed picture. As such, storage mediums have become an integral part of our digital lives, whether our files are stored on internal or external hard or solid-state drives, or in SD cards and flash drives. There is an aching point, though. Just as a document is lost in the physical world, digital files can disappear from storage mediums, too, thanks accidental deletion, drive formatting, a disk’s failure, and more. It’s at these points that data recovery software can help.
Top Data Recovery Software for Mac
|Editor's Choice 2019|
When emergency situations with file disappearance kicks in, users need powerful utilities to bring back the lost data. CleverFiles' Disk Drill is one of these tools designed for macOS. The software will scour the whole drive for any traces of data and present a list of recoverable files. Its success depends on the scan method chosen by the user but in most cases it will be able to identify, preview, and recover the data that the user thought to be lost forever.
A lifetime Disk Drill license costs $89 and users can install it on three Macs, but before paying it is also possible to test the software's capabilities by using the free version. This will give the user an idea of which files are recoverable and which aren't and know if it’s worth buying.
Stellar Mac Data Recovery
The data recovery part of Stellar's software palette, Stellar Mac Data Recovery is a powerful do-it-yourself utility to get data back from any Mac computer. On launch, users can personalize the software's search by applying filters and instructing the software to ignore all other document types. This a handy way to get targeted results right from the start.
As with most data recovery software, Stellar scours through the hard drive and looks for traces of code to identify accidentally removed data. The abilities of all data recovery software is limited by the number of file types its developers have taught it to recognize, but Stellar can do much more than just that: if the user knows what code to look for, they are able to teach the app to look for specific file types not included in its database. This extends the app's reach far beyond the base of the developers. The tool costs $79.99 per year or $99 for a lifetime license, however, users can test the app's capabilities by using the free version.
Mac Data Recovery Software Comparison
The success of a data recovery scenario depends on multiple factors and in fact the operating system in use is one of them. Each OS uses a proprietary file system that maps the physical drive and creates a logical drive – in other words a digital abstraction of the physical hardware – that the desktop OS is capable of reading.
While the algorithm used by data recovery software doesn't differ much between Windows and a macOS, there are tiny things that make a difference such as support of code, which here means file types that the software is able to recognize and reconstruct based on the code it finds on the hard drive. When comparing solutions for the same OS, users would be smart to first check the number of supported file types, its advanced filtering options, and preview functionality, features that are lifesavers when it comes to data recovery.
Mac Data Recovery 101
Macs run on an Apple-developed operating system, macOS (formerly OS X), which uses one of two proprietary file systems: either HFS/HFS+ for older systems or APFS on modern Macs running High Sierra or later. Windows systems cannot read or write to these file systems, though Macs are able to do so on drives using Microsoft's proprietary file systems (such as FAT, exFAT, and so on).
When users install an operating system onto a computer or an external hard drive, the OS first needs to format that drive meaning that it has to map and create a logical disk of a file system that it is able to read and write to. This is an automated process and users won't have to deal with it unless they are formatting an external drive to make it macOS compatible.
Every file a user saves on the storage medium is actually a string of binary data that is given a logical address, which is stored in a reference table that the operating system reads each time a user wants to access a file. With HFS+ this special table is the catalog file and it details the folder and file hierarchy of the volume, containing data about each file and its location on the logical disk, among lots of other important information that the file system needs.
What Happens When a User Deletes Data From a Storage Device?
When it comes to file removal there is a major difference between solid-state drives and hard drives. Unfortunately, data recovery via software is currently limited to only hard drives, so we will focus on these storage mediums.
Upon deleting a file, the operating system doesn't actually remove the file from the drive but instead it hides it from the user and removes any traces of its logical addresses stored in the catalog file, which direct the file system to the erased document. Since the content is left intact and the space it occupies is marked as available to use, data recovery becomes possible on an HDD provided the file wasn't overwritten by the operating system.
How Mac Data Recovery Software Works
DIY data recovery apps use powerful algorithms combined with a database of file signatures, which gives the software the knowledge of what to search for. For example, if the software doesn't know what a text document or email “look” like, then it won't be able to identify it in the sequence of binary data that it will read through when analyzing a hard drive. For that reason, data recovery apps know to search for specific information such as the header of a file or metadata used by a computer program so that can deliver results.
How Deleted Files Are Recovered on macOS
Data recovery apps are built on the open secret that the data is still on the hard drive even after the user has deleted it. By using powerful algorithms, the apps will first check the catalog file about the overall structure of the logical drive and then start looking for older copies of the catalog file that contain important data such as the logical address of the file that was initially ‘erased’ by the user. If you are looking to recover the data of a lifetime – for example, due to a wrong click on a prompt while installing Boot Camp that caused the loss of a partition – then there is good news: the HFS+ file system usually keeps a secondary copy of the catalog file, so a deep scan can produce results so long as the data wasn't overwritten.
Things work a bit differently on APFS because Apple doesn't use any of the key files (such as a catalog file) that are available in HFS+ but instead a technique called copy-on-write, which is still valuable from a data recovery perspective. In other words, don't panic! It is still possible to recover your data if you are running macOS 10.13 High Sierra or later with data recovery software that supports APFS.