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FreeBSD: choose an image before preparing media
To install FreeBSD on a PC from USB, look for a memstick.img image matching its architecture. For an optical or virtual optical drive, choose an ISO. Check the downloaded file before writing it to media.
1. Choose version, architecture and format
The official Get FreeBSD page listed 15.1-RELEASE as a production release on 22 October 2026. Use the published releases section for an everyday installation; development images serve a different purpose.
Then check supported platforms and peripherals. amd64 means x86-64, including compatible Intel PCs; aarch64 means 64-bit ARM. “64-bit” alone cannot distinguish the two, and a compatible processor does not guarantee support for every peripheral.
| Format | Use | Connection for the base system |
|---|---|---|
memstick.img | Installation from USB | Installation files included |
mini-memstick.img | USB installation with downloads during setup | Required |
disc1.iso or dvd1.iso | Optical media or a virtual optical drive | Installation files included |
bootonly.iso | Small boot media | Required |
| VM image | Preinstalled system for a compatible virtual environment | Depends on subsequent tasks |
Applications added later may require network access. For a specific ARM board, start with its documentation and the image specified for that hardware.
2. Verify the file before use
Match the file to the SHA256 or SHA512 record for the same release, architecture and format. Compare the full filename: a compressed image and its decompressed contents have different hashes.
On Windows, PowerShell Get-FileHash calculates SHA256:
Get-FileHash -LiteralPath '.\EXACT-FILENAME' -Algorithm SHA256On FreeBSD, use the sha256 command documented in the manual:
sha256 'EXACT-FILENAME'Replace the example with your actual downloaded filename, including its extension. Compare the complete resulting value with the matching reference. If they differ, do not use the file: check the selected reference, then download again if necessary.
The project also publishes signed checksums for FreeBSD 15.1. SHA256 checks integrity; authenticity also requires verifying the signature using a key whose identity has been established. A value copied from an unknown source is insufficient. For another release, use its own signed checksums.
3. Prepare the USB drive and target disk
The FreeBSD installation handbook describes writing a memstick.img image, including Image Writer on Windows or dd on relevant systems. Write the image to the device; do not simply copy the file into a USB folder.
Writing erases the selected media. Back up its contents, identify the drive by name and capacity, and check the destination before confirming. Device names depend on the computer: do not copy an example’s device name without checking.
Boot from the media using the hardware’s boot menu. Before partitioning, separately verify the disk where FreeBSD will be installed and data to retain. Prepare an independent backup and a way to recover the previous system.
4. Distinguish fresh installation from upgrade
Fresh installation: follow the bsdinstall steps in the handbook linked above, then configure accounts, networking and applications. For a graphical workstation, the desktop chapter describes additional steps.
FreeBSD already installed: read the 15.1 upgrade instructions. They distinguish traditional base-system management from package-based management. Check your starting release and method before following a procedure; also back up service configuration and data.
Finally, check the chosen release’s support period. Our FreeBSD profile helps prepare applications and hardware; the BSD category lets you compare projects.