I accidentally formatted my USB drive and lost several important files. I haven’t saved anything new to it yet. What’s the safest way to recover the deleted data without causing further damage?
Stop using the USB drive immediately.
Do not format it again, run CHKDSK, copy anything onto it, or recover files back to the same drive. A quick format often removes the file-system records without immediately erasing all file contents, so the fact that you have not written anything new gives you a better chance. A full format, secure erase, or hardware-level flash cleanup is a different story and may leave little recoverable data.
The safest DIY approach is to make a sector-by-sector image of the USB onto another drive first. Work on that image rather than repeatedly scanning the original. If the USB disconnects, reports the wrong capacity, gets hot, or makes the computer freeze, stop. Those symptoms can indicate failing hardware, where repeated attempts may make recovery harder.
For a healthy drive, TestDisk may restore a lost partition or damaged file system, while PhotoRec can carve files from the raw data when names and folders are gone. PhotoRec often recovers the contents but gives them generic filenames, so expect some sorting afterward. Commercial recovery software may offer a more convenient preview, but the same rule applies: install it on your computer and save recovered files to a completely different drive.
If the files are genuinely irreplaceable, skip experimentation and contact a recovery specialist. Every DIY scan carries some risk, especially if the USB itself is unstable. Whatever route you choose, keep the original untouched until you have checked that the recovered copies actually open.
Find a second drive with enough free space for the entire USB capacity plus the recovered files. A 128 GB USB needs roughly 128 GB just for the raw image, even if it only contained 10 GB of data. People often miss that and end up writing results back to the USB out of convenience.
I agree with @goldenadmin about imaging first, but make sure it is a true sector-by-sector image, not an ISO or a normal file copy. A tool such as ddrescue is useful because it can read cautiously and resume if the connection drops. Keep the original unplugged once the image is complete, then scan copies of that image if you want to try different recovery programs.
Set expectations based on the type of format. After a quick format, recovery may be fairly good, but folder names and filenames can still be missing. If it was a full format or the drive was encrypted, the odds drop sharply. Recover everything to the second drive, open a sample from each file type, and verify the important files before doing anything else with the USB.
Stop plugging it back in just to check whether the files returned. After making the image, scan that image with more than one recovery tool because results can vary, especially for damaged folder structures. If the files are truly irreplaceable, skip DIY attempts and contact a recovery lab before repeated reads or a failing USB controller make things worse.
Do not let TestDisk write a “fixed” partition table to the original USB. That turns a recovery attempt into a repair attempt, and repairs can overwrite evidence you still need.
Make the sector image, duplicate that image, and experiment only on the duplicate. If a tool offers “repair,” “write,” or “save changes,” point it at the copy. Keep a clean master image untouched so a bad choice costs time, not the remaining data.
And don’t trust a successful preview. Recover files to another drive, then open the full documents, videos, and archives. A thumbnail or filename can survive even when the actual file is incomplete.
Not saving anything yourself does not guarantee the USB has received no new writes. Simply mounting it can let the operating system create indexing or system folders, so leave it unplugged until you are ready to image it.
When making that image, verify the source and destination by model and exact capacity before clicking anything. Mixing them up is the easiest way to overwrite the USB you are trying to recover. Disconnect unrelated external drives, save the image as a file on an internal or separate external disk, then unplug the original USB and work only from a copy of the image.
Start recovery in read-only or scan mode. Try file-system recovery first if preserving names and folders matters, then use file carving if that fails. Save every result elsewhere. As @socket.git noted, previews are weak evidence, so test complete documents, archives, photos, and videos rather than assuming a visible filename means the file survived intact.
If the USB repeatedly disconnects, changes capacity, or reads extremely slowly, stop scanning it. At that point the problem is no longer just an accidental format, and creating the image may need professional hardware rather than another software attempt.