Install f3 with Homebrew, apk, apt, dnf, MacPorts, Nix, zypper

Project links

• Homepage
• Repository
• Upstream docs
• Package manager page

Commands and aliases

• f3read
• f3write

Project history

F3 began in 2010 after Michel Machado bought a 32 GB microSDHC card for an Android phone and found it failed when filled. The official history says the project was inspired by counterfeit-flash reports and by H2testw, whose algorithm was documented but whose implementation was Windows-only and not open source.

The original F3 implementation split the H2testw-style test into `f3write` and `f3read`: one fills available space with test files, and the other validates the data. The toolkit later grew Linux-only direct-device tools: `f3probe` to identify fake drives and real sizes quickly, `f3fix` to create a usable partition matching real capacity, and `f3brew` to help developers infer how fake drives behave.

The changelog records a long maintenance line from version 1.0 in August 2010 through version 10.0 in April 2026, with platform support, extra tools, portability work, and newer probing algorithms added over time.

Adoption history

F3 became the Unix-like answer to H2testw for users who needed to test flash media outside Windows or wanted auditable source. Its docs explicitly cover Linux, macOS, Windows/Cygwin, FreeBSD, Docker-based workflows, Homebrew, and MacPorts installation paths.

Package-manager adoption follows the practical need: F3 is the small CLI people install before trusting cheap SD cards, USB sticks, camera cards, or marketplace flash media. The input package facts list it across Homebrew, Debian, Ubuntu, Fedora, Alpine, MacPorts, Nix, and openSUSE.

How it is used

The conservative workflow is `f3write` on a mounted filesystem followed by `f3read` on the same path. This fills free space with test files and verifies whether the drive returns the same data, while also estimating write and read speeds.

`f3probe` is the faster destructive path for large media because it works directly on an unmounted block device and writes only what is necessary to infer real capacity. `f3fix` then uses probe output to create a partition that fits the usable portion of a fake device.

The docs repeatedly warn that testing suspect media can destroy data, especially because fake devices may overwrite earlier sectors while pretending to have more capacity.

Why package nerds care

F3 is a classic package-nerd utility because it turns a hardware scam into a reproducible command-line test. It is small C code, works in scripts, has simple executables, and answers a question package managers often face indirectly: can this storage device actually be trusted?

It also matters culturally as an open-source, cross-platform counterweight to H2testw. The file format compatibility and staged tool evolution show a pragmatic Unix approach: first reproduce the trusted test, then add direct-device probes and repair helpers.

Timeline

• 2010: Project started after a fake 32 GB microSDHC card exposed the need for an open-source H2testw-like tool.
• 2010: Version 1.0 initial release.
• 2011: Version 2.0 adds macOS support.
• 2014: Version 3.0 adds Windows/Cygwin support and adopts H2testw's file format.
• 2014: Version 4.0 adds FreeBSD support.
• 2014: Version 5.0 adds experimental `f3probe` and `f3fix`.
• 2015: Version 6.0 adds experimental `f3brew`.
• 2017: Version 7.0 marks `f3probe`, `f3fix`, and `f3brew` stable for Linux.
• 2025: Version 9.0 adds portability improvements and GitHub Actions testing.
• 2026: Version 10.0 adds a new `f3probe` probing algorithm and moves the codebase to C17.

Related projects

• H2testw is the Windows tool and file-format reference that inspired F3.
• FakeFlashTest and related flash-test tools occupy the same counterfeit-storage detection niche.
• Homebrew and MacPorts are documented install paths for macOS users.

Sources

• https://fight-flash-fraud.readthedocs.io/en/latest/
• https://fight-flash-fraud.readthedocs.io/en/latest/history.html
• https://fight-flash-fraud.readthedocs.io/en/latest/usage.html
• https://github.com/AltraMayor/f3
• https://github.com/AltraMayor/f3/blob/master/changelog
• https://api.github.com/repos/AltraMayor/f3