Fast
A full card is checked in seconds. Two 4 TB drives are indexed in about ten.
Know your card is backed up. Before you format it.
SD CardCheck reads how your camera organized the card, finds every photo and clip on your backup drives — even renamed or re-sorted — and proves each copy byte by byte.
Version 0.0.15 · 5 MB · macOS 14 Sonoma or later · Reads your card, never writes to it · No account, no cloud
How it works
Three steps from card to confidence.
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1
Insert your card
SD CardCheck notices it and remembers your backup drives, so the next card is one click away.
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2
Press Check
In seconds you see what’s backed up and what’s missing. Then it keeps going and reads every byte, automatically.
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3
Format with confidence
When every file is verified on two separate drives, SD CardCheck says Safe to format — and shows you how in your camera.
Camera-aware
It knows how your camera fills a card.
Cards aren’t just folders of files. Sony writes clips to PRIVATE/M4ROOT and names photo folders by date, cameras add thumbnails, proxies and databases, and macOS sprinkles hidden ._ files everywhere.
SD CardCheck understands all of it. It checks the shots that matter — RAW, JPEG, HEIF and video — and tells you plainly what it skipped and why.
- Sony
- Canon
- Nikon
- Fujifilm
- Panasonic LUMIX
- OM System
- GoPro
- DJI
- Insta360
- Blackmagic
- RED
- Leica
What’s on A7 IV
- RAW photos
ARW476 - Video clips
MP463 - Clip metadata
XML63Optional - Thumbnails & proxies
JPG63Not needed - Camera database
BIN, BDM9Not needed - Hidden system files
._*12Ignored
Shoot RAW + JPEG but only keep the RAWs? Choose RAW only — a JPEG without a RAW twin is still checked.
Proof, not guesses
Same name and size isn’t the same photo.
Most tools compare file names and sizes. On real backup drives, that’s not enough: two different photos can share both. SD CardCheck compares the actual content of every file — so a different photo under the same name is caught, and a renamed or re-sorted copy is still found.
- Seconds first. Missing files show up almost immediately.
- Then every byte. It re-reads each file and its copy straight from the drive and compares them.
- Real drives, not folders. Two folders on one SSD count as one copy — never two.
Why SD CardCheck
Checks what’s already copied — however you copied it.
Offload apps verify the copies they make. Photo importers keep track of what they’ve imported. SD CardCheck answers the question that’s left: is everything on this card already on my backups — no matter which app copied it, or where it ended up?
| Feature | Offload apps | Photo importers | SD CardCheck |
|---|---|---|---|
| Checks a card you’ve already copied — with any app, by hand or in Finder | Only its own transfers | Only its own imports | |
| Finds your shots after another app renamed or re-sorted them | Only its own renames | Only in its catalog | |
| Proves each copy byte for byte | While copying, and from its own hash lists | Varies | |
| Checks every backup drive you have, all at once | The drives it copied to | — | |
| Shows where every shoot ended up on each drive | In its own logs | In its catalog |
Keep using the offload app or importer you love — SD CardCheck independently checks the result before you format.
By shoot and date
Organized the way you shoot.
Every card is grouped into shoots — one camera, one folder, one day — and each shoot shows exactly where it landed on your backup: your Lightroom import, your Final Cut footage folder, your dated archive. However you work.
Copy what’s missing
Missed a few?
Fixed in one click.
SD CardCheck copies only what’s missing — next to the rest of that shoot, into a new folder beside it, into dated folders, or as an exact mirror of the card. You see every destination before anything is written.
- Never overwrites. If a different file already has the name, the copy gets a number instead.
- Verified as it copies. Each copy is flushed to the drive, read back and compared before it counts.
- Your folder, picked in Finder. No paths to type — and it remembers the spot for next time.
- Capture dates kept. Your files keep their original dates.
Safe to format
The green light you’ve been waiting for.
SD CardCheck only says Safe to format when every file is verified byte for byte on two separate drives — and nothing on the card was left out of the check. Then it tells you exactly how to format in the camera you shot with — and ejects the card for you.
And the little things
Built for card day.
Recent cards
Reopen any card you’ve checked — no rescan. Even after it’s ejected.
Show on drive
Jump from any photo to its backup copy in Finder. Quick Look RAW and video.
Next card
Insert a card and SD CardCheck offers to check it against the same backups.
Eject
Done? Eject right from the result. The card stays in your recent list.
Photos, video, audio
Check any combination — or only RAWs, or only JPEGs.
Reports
Export a spreadsheet of every file, its status and where its copies live.
Scan a card
See every shoot on a card — days, cameras, sizes — before you back it up.
Any backup
Check the same card against another drive, or add one, without picking the card again.
Nothing left out
Checked only photos? It says “100% of photos” and reminds you about the videos.
Your folders
Pick where copies go in Finder. Open, show or add them to Lightroom after.
Feels at home
A native Mac app, with light and dark mode and keyboard shortcuts.
Safe by design
Your card is read, never written.
- Read-only on your card. Checking never changes a single file on it.
- Everything stays on your Mac. No account, no cloud, no tracking.
- SD CardCheck never erases. Formatting happens in your camera, when you decide.
Why I made SD CardCheck
As a working photographer and videographer, the part of the job I dreaded most was formatting cards. After a shoot I’d get back to the office, offload everything — and then it was time to format.
I’d highlight the photos and clips to make sure everything copied, but that took time, especially after an adventure shoot, a card that spanned several days, or one that had been through more than one camera. Formatting turned into hours of cross-checking, sometimes a whole day.
I wanted a tool to clear that block in my workflow, so I built my dream app: SD CardCheck. Insert a card, press one button, and know every file is backed up, byte for byte, on every drive.
Now formatting a card is stress-free.
Photographer, videographer and maker of SD CardCheck · gabesilverstein.com
FAQ
Questions, answered.
Does SD CardCheck change anything on my card?
No. Checking only reads. The one thing SD CardCheck can write is copies of missing files — onto your backup drive, into a folder you approve, and never over an existing file.
Does it work with my workflow?
Yes. SD CardCheck finds your files wherever they ended up — a Lightroom or Capture One import, a Photo Mechanic ingest with new names, Final Cut or Premiere footage folders, dated archives — on any drive, including network drives. It doesn’t need the card’s folder structure copied.
What does “Safe to format” mean?
Every photo and clip you chose to check has a byte-for-byte verified copy on at least two separate physical drives (you can change the number in Settings). Two folders on the same drive count once.
Why format in the camera instead of on my Mac?
Cameras set up their own folders and database files when they format a card. A card erased on a computer can show errors or slower writes. SD CardCheck shows the exact menu path for the camera it found on your card.
Which cameras and files does it understand?
Any card with a standard DCIM folder, plus camera-specific layouts from Sony (including XAVC clips and date-named folders), Canon, Nikon, Fujifilm, Panasonic, OM System, GoPro, DJI, Insta360, RED and Blackmagic. RAW, JPEG, HEIF, MP4, MOV, MXF, BRAW, WAV and more.
How fast is it?
On a real 18 GB Sony card checked against two 4 TB drives, the first answer arrives in under ten seconds. Reading every byte of the card and its copies took a little over two minutes.
Can SD CardCheck guarantee I won’t lose anything?
No software can. SD CardCheck is a tool to help you check your own backups; the decision to format, erase or reuse a card is always yours. Keep more than one backup, and see the disclaimer: Gabe Silverstein isn’t responsible for any lost data.
Does it need the internet?
No. SD CardCheck works entirely on your Mac. There’s no account and nothing is uploaded.
