Introducing Crooli Flash
Crooli Flash is a free USB tool for Mac and Windows. Flash an ISO, check every byte, or format a drive, then install it with a single pasted command.
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A calm way to put an operating system on a USB stick.
Crooli OS needs a USB stick to get started, and every tool for making one felt like more work than the thing it was for. So we made our own. Crooli Flash is a small, quiet app for Mac and Windows that writes an ISO to a drive, checks that it worked, and formats drives when you need a clean one. It lives at [crooli.com/flash](/flash).
Three jobs, done well
- Flash. Pick an `.iso` or `.img`, pick a drive, press Flash. Hybrid images like Crooli OS are written exactly as they are.
- Verify. After writing, it reads the whole drive back and compares a SHA-256 fingerprint with the image, so you find out now rather than at boot. Verify also works on its own, to check a stick you made earlier.
- Format. FAT32, exFAT, NTFS on Windows or Mac OS Extended on a Mac, with a quick erase or a full one that zeroes every byte.
It only lists USB drives, never your system disk, and it asks before it erases anything.
Installed with a command, on purpose
There is no download button. A file downloaded in a browser is marked as coming from the internet, and for an app that is not notarized, macOS then stops it and sends you into System Settings to approve it. Windows does the same with SmartScreen. That is a lot of clicking for a USB tool.
So Crooli Flash is installed by pasting one line. On a Mac:
```sh curl -fsSL https://crooli.com/flash/install.sh | sh ```
On Windows, in PowerShell:
```powershell irm https://crooli.com/flash/install.ps1 | iex ```
The command fetches the same release without the "from the internet" mark, so the app simply opens. Both scripts are short and public, and you can read them before you run them. Once it is installed, it updates itself when a new version is out.
Public, not open source
The code is on GitHub at xandertaylorx/crooli-flash, so you can read exactly what runs on your computer. It is not open source: you can read it and use the official builds, but not copy or redistribute it.
Get it
Open [crooli.com/flash](/flash), copy the command for your computer, and paste it. If you are making a stick for Crooli OS, [the launch post](/news/crooli-os-is-live) has the rest of the steps.