Lénaïc Bagnères, lenaicb@singularity.fr
Personnal website
Cute duck

iconDebian GNU/Linux

iconf3 - Fight Flash Fraud (2022)

iconf3 - Fight Flash Fraud:
"f3 is a simple tool that tests flash cards capacity and performance to see if they live up to claimed specifications. It fills the device with pseudorandom data and then checks if it returns the same on reading.

F3 stands for Fight Flash Fraud, or Fight Fake Flash."


When I receive or buy an (USB) flash drive, I check it using f3.

For the story: at my work in ~2019, they bought USB flash drive of 2 GB. On this device, everything your write after the first gigabyte is written 'correctly', appears but you can read it. Using /dev/null is better.


You flash drive is already formated using your favorite filesystem (or not). The device is mounted, you can write and read files.

The Commands I Use

Write files in the device:

f3write /media/DEVICE/

Read the files in the device:

f3read /media/DEVICE/

In my memories, f3 proposes the command to resize the filesystem at the real size.