Frequently asked questions

Flashing an image to a USB drive erases everything on that drive. That is true of every imaging tool, and Flint makes it explicit: it writes directly to the physical disk, shows you the exact drive (model, size, serial), re-detects the drive immediately before writing, and requires a typed confirmation — you type the required text to arm the operation. There is no accidental double-click path to erasing a drive.

Destructive operations only accept whole-physical-disk paths (\\.\PHYSICALDRIVEn) for detected removable drives, and refuse volume paths like E:. All writes are direct disk writes with typed confirmation. Still, always double-check the drive card before arming a write — no tool can protect against a user confirming the wrong stick.

The executable is currently unsigned — code signing requires a certificate from a paid CA, which this open-source project doesn't have yet. Unsigned downloads trigger the “Windows protected your PC” dialog. Click More info → Run anyway, and verify the download first with certutil -hashfile flint.exe SHA256 against the checksum published on the release page.

Yes. Flint writes raw images to any removable USB drive on Windows, regardless of what the drive previously contained. You can flash Linux ISO images (including live systems with persistence support) and macOS-style hybrid images that can boot on other machines. Flint itself only runs on Windows.

Since Flint is a single portable flint.exe with no installer, yes — drop it on any drive (including the one you're about to image) and run it from there. Its settings and flash history are stored in your Windows app-data folder, not next to the executable.

Verification re-reads the entire drive and hashes it — the same amount of data as the write, so similar time. That's the price of knowing the image landed correctly. You can skip verification for image formats that can't be compared, but skipping is always an explicit choice.

Zero fill, a single random pass following NIST SP 800-88, and the classic DoD 5220.22-M three-pass wipe (zeros, ones, random). Every wipe ends with a read-back verification pass confirming the final pattern — an unverified wipe is reported as failed, never as success.

Cheap USB sticks sometimes contain sectors that fail on read or write. Flint's bad-block scan retries unreadable sectors during verification and reports their locations, so you can see the drive failing instead of discovering it months later when the data is gone. Fake-capacity drives (claiming 64 GB, actually 4 GB) are exactly the scenario this catches.

Open an issue on the GitHub issue tracker. Go to the History page in Flint and click Export diagnostics… — it bundles the app version, drive list, flash history and logs into one text file. Attach it to the issue; it makes debugging dramatically faster.

Free, forever, no telemetry, no ads, no accounts. Flint is MIT licensed open-source software — read, modify and redistribute freely, subject to the license terms in the repository.

Yes — that's a first-class use case. The headless CLI (flint list, flint flash and friends) plus fleet mode (flint flash-all) and the multi-image queue is designed for imaging multiple drives unattended, and the flash history gives you a per-drive audit trail of every operation.

About once a week it quietly checks the GitHub release feed for a new version. When one exists, it offers to download the new flint.exe — and verifies the download's SHA-256 against the published checksum before keeping it; a failed checksum discards the file. You can also check manually at any time from the ⋮ menu (Check for updates…). If the release feed is unreachable, the check is reported as unavailable — it never blocks the app and no update is installed without your say-so.

Yes — Settings has three themes: dark (default), light, and high-contrast. They switch live and persist between sessions. High-contrast is intended for accessibility.

Everything is per-user and local: %APPDATA%\Flint\settings.json and %APPDATA%\Flint\history.json, with logs in %TEMP%\flint-startup.log and %LOCALAPPDATA%\Flint\crash.log. Nothing is stored next to the portable executable, and nothing is uploaded anywhere.

Writing to \\.\PHYSICALDRIVEn (whole-disk I/O), locking volumes during a wipe, and applying Windows images with dism all require elevation on Windows. Flint relaunches elevated when it needs to, and asks before triggering a UAC prompt unless you turn that off in Settings.

Flint is an open-source alternative to Rufus, balenaEtcher and similar tools — with verification as the core idea. Like them, it writes ISO and DD images to USB drives. Then it re-reads the entire drive and compares SHA-256 hashes byte-for-byte, reporting exact mismatch offsets instead of assuming the write worked. It's Windows-only, a single portable executable with no installer, includes a headless CLI for IT imaging, and is MIT licensed.

No — Flint is a Windows application. It runs on Windows 10 and Windows 11 (64-bit) only. The drive images it writes can be for any system: Linux, Windows, macOS-style hybrid images and more all work as long as you flash them from Windows.