Quick Summary
It is possible to recover files from an erased Mac, but success depends on several factors. Immediately stop using the erased Mac, as continuing to write data makes recovery harder. Use data recovery software designed for Mac as soon as possible after erasing. The longer you wait, the lower the chance of recovery. Be prepared to try multiple software options, as results vary. Recovery from SSDs is more difficult than traditional hard drives. Prior backups offer the best chance for recovery.
What Does “Erased” Mean on a Mac?
When you “erase” a Mac, it does not actually wipe the data from the drive. The erase process simply removes pointers to the files and marks the space as available for new data. The files remain intact until they get overwritten. This is why you have a window of opportunity to use data recovery software to restore erased files. However, there are varying levels of erasing a Mac:
Standard Erase
Doing a standard erase on a Mac simply performs a fast format of the drive. It deletes the directory structure and space allocation tables, making files inaccessible through normal access. However, the files themselves remain on the drive until overwritten. This makes data recovery possible.
Full Erase
A full erase goes a step further by writing zeros to the data blocks on the drive. This makes traditional file recovery more difficult, but not impossible. Advanced data recovery firms claim success in recovering files from fully erased traditional hard disk drives by scanning for file fragments. However, full erasure reduces the chances of recovery significantly.
Multi-pass Erase
Taking full erase even further, multi-pass writes random data patterns multiple times to completely obscure the existing data. This significantly decreases the chances of recovering any data. Most data recovery software cannot recover data from a multi-pass erase. However, it’s still possible for someone with advanced skills and equipment to recover some fragments. The more passes, the lower the chance of recovery.
When to Stop Using an Erased Mac
As soon as you realize important files are missing from your erased Mac, stop using it immediately. This is critical to avoid overwritten files that are no longer recoverable. Any additional data written to the drive decreases your chances of getting files back.
Power down the Mac and remove the drive if possible. Don’t boot up the erased Mac again until after attempting data recovery. If the erased drive is your startup disk, boot from an external drive instead. The less you do on the erased disk, the better.
Choose Mac Data Recovery Software
Many data recovery apps exist for retrieving files from an erased Mac. Select software designed specifically for Mac file systems like HFS+ or APFS rather than Windows programs. Here are some top options:
Disk Drill
Disk Drill is a popular Mac data recovery app that scans erased hard drives and SSDs to find recoverable files. It can rebuild file structures after erasure to make copies accessible again. Disk Drill offers a free trial so you can see if your files can be recovered before purchasing.
Data Rescue
Another excellent choice is Data Rescue from Prosoft Engineering. Data Rescue claims a high recovery success rate for photos, documents, music and other files from erased, corrupted or damaged Mac drives. It scans efficiently to minimize extra disk access. Data Rescue is available in home, professional and enterprise versions.
R-Studio
R-Studio from R-Tools Tech offers deep scanning capabilities to find files on erased or corrupt Mac devices. It supports recovery even from formatted or repartitioned drives. R-Studio runs advanced algorithms to locate files based on data patterns rather than file system structures. It can recover from Mac drives as well as iOS and Android devices.
DiskWarrior
While not solely a data recovery app, DiskWarrior from Alsoft is useful for rebuilding damaged directories to make recovered files accessible again after erasure. It can rebuild HFS+ and APFS directory structures after data loss. DiskWarrior often finds files when other utilities fail and is a helpful compliment to recovery apps like those above.
Act Quickly for Best Results
Time is critical when attempting data recovery from an erased Mac. Immediately stop using the drive and run data recovery software as soon as possible after erasure. The longer you use the Mac and write new files, the lower your chances of recovery as data gets overwritten.
Most recovery software scans available data quickly, minimizing disk access. However, advanced deep scanning searches take longer and reduce your window for recovery. Start quick scans first, then deep scanning if needed. Don’t scan longer than needed to locate your critical files.
Understand SSD vs HDD Recovery
Recovering erased files from a solid state drive (SSD) is more difficult than from a traditional hard disk drive (HDD). When files are erased on an SSD, the drive controller immediately reallocates sectors tagged for deletion. Wear leveling routines further distribute deleted data across the drive over time. This obscures erased files quicker than on HDDs.
However, data recovery is still possible on recently erased SSDs using specialized software tuned for SSD file systems like APFS. Scan quickly before extensive reallocation occurs. Recovery gets progressively lower over time. Heavily used SSDs have lower chances due to increased data rewriting.
Use Multiple Software Options
No single data recovery app finds every deleted file. File systems are complex, so different programs use varying recovery techniques with different results. Running multiple recovery tools can help locate files missed by the others.
For example, use Disk Drill for a quick initial scan. Then run Data Rescue for deep scanning recovery. R-Studio can perform more advanced scans of memory chips themselves. Using multiple apps together increases your chances versus relying on just one.
Consider a Clean Room Recovery
For greatest recovery chances from a badly erased Mac, consider sending it to a professional clean room recovery service. They disassemble drives in dust-free rooms and use specialized equipment to read raw data off the memory chips. This is expensive but can recover data otherwise lost even from drives with major erasure or damage.
Prioritize Recovering Important Files
If a complete recovery isn’t possible, focus efforts on your most important files. Sort through recoverable data and selectively save essential documents, photos or other critical items. Leave the drive alone again once your key files are recovered to avoid overwriting anything else.
Critical files may recover more easily than large files like video. Recoverability can vary by location on the disk as well. Don’t waste time on low priority files if your window for recovery is limited.
Prevent Erasure by Backing Up
The best way to avoid needing data recovery is having a current backup of your important files. Regularly create backups to external drives so you always have another copy of critical data. Cloud backup services offer offsite protection of files.
Backup key files before performing any erase, upgrade or configuration change on your Mac. Verify backups periodically by viewing contents and doing test restores. With a recent backup, erasure is just a minor inconvenience.
Can You Recover Files on an Erased Mac with Time Machine?
If you have a current Time Machine backup, you may be able to easily recover erased files without third-party data recovery software. But Time Machine must be intact after erasure.
If you erased the entire Mac drive including the backup partition, Time Machine is erased as well. Then recovery requires unerasing the Time Machine drive first before you can access backups. Don’t use the Mac until recovery apps unerase the backup drive.
If just the main system partition was erased but Time Machine is still available, you can readily recover files from backup. Simply scan the Time Machine drive with data recovery tools to make backups accessible again. Then restore missing files from your backup.
How Long Does Mac File Recovery Take?
The speed of recovering erased files depends on various factors:
– File system and type of erasure – APFS and SSDs take longer than HFS+ on HDDs. Multi-pass erasure is slower.
– Scan type – Quick scans are faster than deep scanning. Media chip-level scans take hours.
– Drive capacity – Larger drives with more data take longer to scan than smaller ones.
– Connection – Faster connections like Thunderbolt speed the process versus USB or wireless.
– Hardware performance – Recovery is quicker on high-end Macs versus older models.
For a quick initial scan of a recently erased 1TB HDD using a Thunderbolt connection and a current Mac, recovery could take 2-3 hours. Deep scanning the same drive might take 8 hours or longer. Scanning a 512GB SSD could go faster at 1-2 hours quick or 4-5 hours deep.
How Successful is Erased File Recovery on Macs?
Recovery rates vary widely based on these key factors:
– Erase method – Standard erase has highest success rate, full erase lower, and multi-pass is lowest.
– Time elapsed – Sooner attempts after erasure recover more files than later attempts.
– Drive type – HDD recovery is generally more successful than SSD, which tends to overlay data quickly.
– File size – Smaller files recover better than larger media files in most cases. Fragments of big files may be recoverable.
– User action – Continuing to use the erased Mac greatly reduces success.
A typical success rate for recovering data from a standard erased Mac HDD using data recovery software soon after erasure might be in the 60-90% range if the disk is not reused. Alternatively, trying to recover files from a heavily used SSD that was multi-pass erased weeks later may only yield 10-30% recovery.
Can You Recover Files after Factory Resetting a Mac?
When you factory reset a Mac using the “Erase All Content and Settings” option, it performs a standard format erasure. This deletes directory structures, but maintains files intact until overwritten. As long as you promptly run data recovery software before reuse, you have a good chance of retrieving much of the original data.
However, stop using the Mac immediately after the reset. Any additional activity risks overwriting deleted files, lowering chances of recovery. The sooner recovery is attempted after a factory reset, the better. Deep scanning recovery software designed for Mac can bring back a majority of files in many cases if the erased drive is untouched.
Can Erased Files be Recovered after Reinstalling macOS?
If you erased your Mac drive while reinstalling macOS, file recovery is still possible, but trickier. The macOS installer does a quick format erasure of the drive before installation. This removes file system structures while maintaining existing data temporarily.
However, the installer then writes tons of new data during OS installation. This progressively overwrites deleted files required for recovery. Plus, using the Mac after reinstall continues the overwrite process.
To attempt recovery in this scenario, immediately stop using the Mac after the reinstall finishes. Remove the drive and connect it to another Mac. Scan the drive with data recovery software before doing anything further. Deep scanning may locate fragments of original files overwritten during installation before they are completely replaced.
Conclusion
While erasing a Mac makes files inaccessible through normal methods, hope exists for recovering deleted data in many cases. Immediately stop using the erased Mac, remove the drive if possible, and use specialized Mac data recovery software as soon as possible after erasure for the greatest chance of getting files back. However, prior backups remain the best way to protect important data from loss due to erasure or deletions. Handle drives carefully, maintain good backups and follow these tips for recovering from accidental Mac erasures when necessary.