FakeFlashTest for Windows

What this utility does

FakeFlashTest is a lightweight program created by the author of RMPrepUSB to verify the true capacity of USB flash drives and SD cards. It helps reveal devices that falsely report large capacities — for example, a device sold as 64 GB that actually only stores 1 GB — and can help you avoid or recover from data corruption caused by counterfeit storage media.

How the checks operate

The application offers two main checks:

1. Quick Size Test
2. Scans and reports the drive’s actual reported size and whether the device appears genuine.

3. Can remove or overwrite existing files on the media, so backing up important data beforehand is strongly advised.

4. Test Empty Space

5. Writes test files into the drive’s available free space to verify that the space is usable and truly available.
6. If mismatches are found (i.e., the device is counterfeit), the process can overwrite data or create corrupted files as part of detection.

Step-by-step: running a verification

1. Insert the USB flash drive or SD card into your computer.
2. Launch FakeFlashTest.
3. Select the “Test Empty Space” option if you want a non-invasive check of free space (this still writes test files to free space).
4. Choose “Quick Size Test” if you want a fast size-and-authenticity check (remember to back up first).
5. Wait for the tool to finish; it will produce a report showing the drive’s real usable capacity and any inconsistencies.

Safety tips before testing

• Always make a backup of any irreplaceable files stored on the device before running either test.
• Prefer the Empty Space test when you want to avoid scanning and overwriting the entire device, but note that it still writes to free space.
• If a test reports that the device is fraudulent, stop using it for important data and consider returning or discarding it.

Other utilities that perform similar checks

• Flash Drive/Card Tester
• DriverIdentifier
• H2Testw

These alternatives also allow you to validate a drive’s true capacity and detect fake storage, each with slightly different interfaces and test methods.

Why it’s useful

Cheap or second-hand storage media sold online sometimes misreport their capacity. FakeFlashTest gives you a quick way to confirm what you actually have, preventing unpleasant surprises when you try to save large files. For anyone who buys low-cost flash drives or memory cards frequently, it’s a practical diagnostic tool to keep on hand.