4 Tools to Test and Detect Fake or Counterfeit USB Flash Drives

There are plenty of fake and counterfeit products around and the world of computers is not exempt. In recent years one area has become more prone to this than any other, and that is flash memory storage. Devices such as USB flash drives, SD/CF cards and even SSD drives have been affected by this problem. Counterfeit USB flash drives seem to be the most common though, there’s so many different types, capacities and speeds that it’s easy to hide them among all the real products.

You may think this problem only affects places like eBay but even Amazon and other legitimate retailers have been caught out too. This is why it’s a good idea to check any flash device you purchase is the product you paid for. Making sure the serial or code number on the stick is legitimate is one way, another is making sure the drive is the size advertised because most fake drives have a lower real capacity than listed by using smaller and much cheaper memory chips. The drive may even be reported as the right size in windows.

Software developers are also aware of this and some have written tools to help you identify if a drive is smaller than you expect and is therefore likely to be counterfeit. Here we have listed 4 for you to try that are designed to check for fake size drives.

1. H2testw

For several years H2testw has been known as THE tool for checking memory based flash drives to see if they are the correct capacity. The problem is it was developed several years ago and the last release was way back in 2008, flash based media is available in much larger capacities now and a scan with H2testw can run into several hours because it hasn’t been optimized to run on big drives.

h2testw main gui

The method used in H2testw, while very slow is still one of the most thorough ways to scan the drive for a fake capacity. It isn’t a fully destructive test because it only checks the free space on the drive, but the best way is to use H2testw on a cleanly formatted device, that way it will be checked completely from the first byte to the last. It works by writing large 1GB files to the free space and then reading them back, the idea being if the read data isn’t the same as what was written, there’s a possible issue.

After it’s done the software leaves the test files on the media, you can erase them if you like or verify them again. If you have the time and want a very thorough test, try H2testw, if not try something that works a bit quicker first. H2testw defaults to German language but you can easily change it in the GUI.

Download H2testw

2. FakeFlashTest

The FakeFlashTest utility is from the developer of the RMPrepUSB multipurpose USB booting suite. One component of the RMPrepUSB program is a small and quick test to check your drive and its real capacity, this is an extended and enhanced version of that which has been released as a standalone executable. Unlike many other tools of this type, FakeFlashTest is quite new so includes optimizations and methods better suited for today’s flash media.


FakeFlashTest tries to fix the main issue with H2testw which is the incredibly slow time it can take for the process to complete on larger and slower flash drives. The first test you can run is similar to the one found in RMPrepUSB and a quick test. This writes and reads 512 bytes of data at set intervals across the drive and so finishes in less time. The second test is very similar to H2testw and writes/reads to all free space on the drive but has been optimized in a number of ways to complete the task much quicker than H2testw.

Do note that the the quick test is destructive meaning anything on the drive will be overwritten, so make sure your files are backed up. The slower test is not meant to be destructive but can still corrupt your files if they are on a bad area of the drive.

Download FakeFlashTest

3. USB Flash Drive Tester

USB Flash Drive Tester is listed by its developer as a generic tool for testing flash drives or SD/CF cards but is especially useful for detecting counterfeit drives with a fake capacity. It works in a similar way to H2testw by writing data to the device, reading it back and then comparing the two for differences. Any errors indicate a problem with the drive.

usb flash drive tester

To run a full test select your flash drive from the drop down and a test type of “write, read and compare”, then start the test. If you don’t have the time to run a full test on a large or slow drive, the data can be written to the drive now and compared later on. Like H2testw this is getting a bit old and comes from 2009, it also requires installation.

Download USB Flash Drive Tester

4. ChipGenius

The programs listed above all work in the same way which is to write data onto the disk and then read it back to see if the data is correct or corrupt. ChipGenius is completely different and actually doesn’t touch the data on the drive at all but instead reads the information from the flash memory chip inside it to see what it is and what it’s true size should be. This might not work all the time but for the majority of counterfeit devices, it should work as intended.


Simply run the program and look for the information about the flash chip inside your device, a line will give the vendor and model number of the chip and its true capacity. If your flash drive is supposed to be perhaps 64GB and the Total Capacity listed is much less than 64GB, then it’s likely a fake drive. Right click in the window to copy the data to the clipboard if you want to manually search or find out more about the chip inside your drive.

Note: Be aware that ChipGenius generates false positives with online virus scanners like VirusTotal. Don’t download the program if this makes you uncomfortable.

Download ChipGenius (Russian site) Direct Download of ChipGenius

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