On an old-style hard drive, deleting a file only marks its space as free, and the data usually sits there until something overwrites it. That is why “undelete” tools and recovery labs can so often bring deleted files back. Solid-state drives (SSDs) work differently. On most modern computers, a file deleted from an SSD is wiped by the drive itself within minutes. This guide explains why, when there are exceptions, and the places worth checking before you give up on a deleted file.
Why SSDs erase deleted files: TRIM
An SSD can’t simply write over old data the way a hard drive does. Flash memory has to be erased before it can be reused, and it is erased in large blocks. To keep the drive fast, the operating system sends a TRIM command whenever you delete a file, telling the SSD which areas no longer hold anything useful. The SSD’s controller then clears those areas in the background, ready for new data.
After a deleted area has been trimmed, most SSDs return nothing but zeros when anyone tries to read it. No software and no lab can recover data that the drive itself has erased. Emptying the Recycle Bin or Trash on a laptop with an internal SSD is therefore usually final.
The same applies to a quick format or a Windows or macOS reinstall on an SSD: the whole drive is typically trimmed, and the old files are gone.
Is TRIM switched on for your drive?
Almost certainly, if it is an internal SSD in a computer from the last decade. You can check:
- Windows: open Command Prompt and type
fsutil behavior query DisableDeleteNotify. A result of 0 means TRIM is on. - Mac: open System Information, choose NVMExpress or SATA under Hardware, and look for “TRIM Support: Yes”.
The exceptions, where recovery may still be possible
External SSDs and USB enclosures
TRIM has to pass from the computer, through any USB adapter, to the drive. Some USB enclosures and docks don’t pass it on, so a file deleted from an external SSD may survive for longer than one deleted from an internal drive. It is not guaranteed, but it is worth acting quickly.
Memory cards and USB sticks
SD cards, microSD cards and most USB flash drives don’t receive TRIM from cameras or most computers. Photos deleted from a camera card are often recoverable, as long as you stop using the card straight away.
Drives where TRIM is off
Older operating systems, some RAID setups and some encrypted or specialist configurations don’t send TRIM. In those cases a deleted file behaves more like it would on a hard drive.
A drive that has failed, rather than files that were deleted
This is the important distinction. If your SSD has stopped being detected, shows the wrong capacity or locked up after an update, your files haven’t been deleted: the drive has developed a fault, and the data is usually still in the flash memory. That is a hardware recovery job, and the chances are often good. See SSD data recovery.
Check these places first
Before assuming a deleted file is gone, look for copies that may exist elsewhere:
- Recycle Bin or Trash, including the Trash inside apps such as Photos (Recently Deleted) and your email program.
- Cloud storage bins. OneDrive, Google Drive, Dropbox and iCloud Drive all keep deleted files for a period, often 30 days or more, in a recycle bin on their website.
- Version history. Files saved in OneDrive, Google Drive or Dropbox can usually be rolled back to an earlier version, even if they were overwritten rather than deleted.
- Backups and snapshots. Time Machine on a Mac, File History on Windows, and the backup software or NAS snapshots on a business network.
- Email and messages. If you sent the file to someone, or received it as an attachment, a copy may still be there.
What to do straight away
- Stop using the computer or drive. Every minute of use gives TRIM and new data more chance to clear what is left.
- Don’t install recovery software on the same drive. Installing it can overwrite exactly what you are trying to recover.
- Unplug an external drive or card and keep it somewhere safe.
- Get an honest assessment before you spend money. A short conversation is usually enough to tell whether a deleted file on your particular device is realistically recoverable.
Talk to an engineer
We’ll tell you plainly if a deletion from an SSD is beyond recovery, and point you to the backups and cloud copies worth checking instead. When there is something to recover, such as a failed SSD, a memory card, an external drive or a hard drive, an engineer evaluates it and gives you a fixed quote, and recovery only starts when you approve it. We work from a copy of the drive, never your only original. More on deleted file recovery.
We work on-site across Los Angeles, the Inland Empire and Ventura County, and by mail-in from anywhere in the US. Call (213) 986-4855 or book data recovery online.