This Free App Tells You Exactly When Your Camera Card Is Safe to Wipe
Stow copies your camera card to two drives, verifies both, and gives you a clear verdict: safe to wipe or not yet. It's free, it runs locally, and it's the only card offload tool that actually tells you what to do next.
Every videographer has been there: end of a shoot day, multiple cards, multiple drives, not entirely sure which copies actually verified and which ones just finished without errors. Most card offload tools show you a checksum. None of them tell you what to do with it.
Stow does. It copies your card to two drives simultaneously, reads every file back off both drives to verify each copy against the source, and then gives you one of three verdicts: not verified, one verified copy, or safe to wipe. Green means green. Nothing else does.
It's free for macOS and Windows, built by Luke Lv at Lumira Studio — a video production company in Hertfordshire, England — and it exists because they needed it on their own shoots.
The problem it's solving
Your Mac or PC doesn't verify what it copies. Files arrive on the destination drive, but the operating system doesn't confirm they match the source. A corrupt copy sits hidden until you're in the edit bay with the original card long since wiped.
Standard card offload tools — Hedge's OffShoot, ShotPut Pro, Pomfort — solve part of this: they checksum the copy and prove the files transferred intact. What they don't do is translate that technical result into a clear, actionable answer. You get a passed verification. You still have to decide what that means.
Stow's answer is the verdict system. It won't call a card safe to wipe unless there are two verified copies on two separate drives. One verified copy holds at amber — it worked, but a single drive is still a single point of failure. Not verified stays red. Only two verified copies on two separate drives turns it green.
What Stow actually does, step by step
- Insert card — Stow detects the camera and files footage into a consistent folder tree automatically
- Pick two destinations — a working drive and a backup
- Stow reads the card once and writes to both drives simultaneously
- It reads every file back off both drives and verifies each against the source using xxHash3-128 and ASC-MHL v2
- It gives you the verdict
Transfer speed is real: the screenshot on Stow's site shows a Sony FX6 card offloading at 877 MB/s. Multiple cards can be queued. It never writes to or deletes from the original card — formatting stays your decision, in the camera, after the verdict is green.
Every run writes a one-page verified offload report to each destination — what was copied, what was verified, the verdict, a per-card clip count, and a checksums.csv. Print it or send it to a client.
How it stacks up against the paid tools
Stow's own comparison table puts it clearly. OffShoot (Hedge) costs $169–$249 one-time. ShotPut Pro is $169 one-time plus update fees. Pomfort runs $199–$899 per year and is Mac-only. DaVinci Resolve's built-in Clone tool is free but limited. All five tools produce checksummed copies. Only Stow produces a safe-to-wipe verdict.
The one missing feature for now: Stow v0.5.0 is Apple Silicon only on Mac (no Intel support yet), and the builds aren't yet signed — which means a one-time Terminal command on macOS or a SmartScreen click-through on Windows. Signed builds are on the roadmap.
Why it's free
Lumira Studio is a video production company, not a software company. Lv's explanation on the product page: "We built Stow for our own sets, and other shooters asked for it. It is free, and it stays free." No paid tier is planned. No account required. No uploads — the entire verification process runs locally.
What's coming in future free updates: custom rename and folder templates, first-class resume for stopped offloads, additional checksum formats (MD5, SHA-256, C4), and cloud destinations for verified transfer to S3 and Dropbox.
The Signal in the Noise
The paid card offload tools are good at what they do. The gap Stow fills isn't technical capability — it's communication. Checksums tell you what happened. Stow tells you what to do next. For solo operators, small crews, and anyone who's ever held a card wondering if it's really safe to wipe, that difference is immediate and useful.
Free download at lumirastudio.com/stow. Apple Silicon Mac and Windows, v0.5.0.
