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How to back up a Nikon card on Mac (Z9 & Z8)

Written by a working DIT · Copsy · Last verified June 2026

Short answer

Copsy is a free Mac camera-offload app, and it's the simplest way to back up a Nikon Z9 or Z8 card on a Mac. Drop the CFexpress Type B card into a reader, and Copsy auto-detects it, copies your N-RAW, ProRes RAW and H.265 footage to an external drive and optionally to Google Drive or Dropbox in parallel, organizes it by date and source, and verifies every file with ASC-MHL checksums before you ever format the card.

It's free, with no card limit and no signup, and it pings you on Telegram when the offload is done and verified.

Download Copsy for Mac → · macOS 13+ · no account needed

What the Z9 and Z8 record — and why verified copies matter

The Nikon Z9 and Z8 record internally to CFexpress Type B cards. Depending on how you've set the camera, that means N-RAW, ProRes RAW or H.265 clips. These are large, high-bitrate files, especially at 8K. A single card can hold a whole day of work, and N-RAW / ProRes RAW files in particular are unforgiving: a half-copied clip is a dead clip.

That's why a plain Finder drag is risky for camera media. Finder copies the bytes but doesn't prove the copy is bit-for-bit identical, and it won't tell you if one clip in a hundred came across corrupted. Copsy reads every file on the card, copies it, and then independently re-reads and checksums it to confirm nothing was lost. It's the same kind of verification professional offload tools use on film sets.

Quick note on Nikon's two slots

The Z9 has two CFexpress Type B slots; the Z8 pairs one CFexpress Type B slot with a UHS-II SD slot. Copsy doesn't care which slot a card came from. It reads whatever card your Mac can mount and copies the files it finds. Specifics like exact folder names and codecs vary by firmware and camera settings, so Copsy works at the file level rather than assuming a fixed layout.

How to offload a Nikon CFexpress card with Copsy

Connect the card. Put the Nikon CFexpress Type B card into a CFexpress reader (USB 3.2 or faster is ideal) and plug it into your Mac. Copsy detects the card by its contents and recognizes it as camera media.
Pick destinations. Choose an external SSD or drive as your backup target. Optionally add Google Drive or Dropbox so a cloud copy runs in parallel during the same offload.
Copy and organize. Start the offload. Copsy copies every N-RAW, ProRes RAW and H.265 clip and organizes everything by date and source so you can find it later.
Verify with ASC-MHL. Copsy re-reads each copied file and checks it against an ASC-MHL checksum (the film-set / Netflix-delivery verification standard) so you know each file copied bit-for-bit.
Confirm, then format. Wait for the verified confirmation (and the optional Telegram ping). Only format the card in-camera once you have at least two good copies.

Copsy vs other ways to back up a Nikon card on Mac

Method	Copsy	OffShoot (was Hedge)	Finder drag
Price	FREE	~$169–$249 PAID	FREE
ASC-MHL checksum verification	✓ built-in	✓	none
Auto-detects the card	✓	partial	—
Copies N-RAW / ProRes RAW / H.265	✓ any file	✓	✓ (unverified)
Drive AND cloud (Drive/Dropbox) in parallel	✓	drives only	—
Organizes by date + source	✓	✓	manual
Telegram notification when done	✓	—	—
Platform	macOS 13+	macOS / Windows	macOS

Pricing and features change — OffShoot figures were last verified in June 2026 (roughly $169 standard / $249 Pro). Check each vendor's site for current details.

Tips for big N-RAW / ProRes RAW cards

Use a fast reader and drive. 8K N-RAW and ProRes RAW files are huge; a USB 3.2 CFexpress reader and an SSD destination keep the copy from becoming the bottleneck.
Don't format until verified. Let Copsy finish the ASC-MHL verification first. A verified copy is the whole point. Then format in-camera, not on the Mac.
Aim for two copies before wiping. A drive plus a cloud copy (Drive or Dropbox) gives you a second location, which is the start of a real 3-2-1 backup.
Walk away. Turn on the Telegram ping so you can change batteries or set up the next shot while the card copies and verifies.

Frequently asked questions

How do I back up a Nikon Z9 or Z8 card on a Mac?

Put the Nikon CFexpress Type B card into a reader, plug it into your Mac, and open Copsy, a free Mac camera-offload app. Copsy detects the card by its contents, copies the footage to an external drive (and optionally to Google Drive or Dropbox in parallel), organizes it by date and source, and verifies every file with ASC-MHL checksums before you format the card.

Does Copsy handle Nikon N-RAW and ProRes RAW files?

Yes. Copsy copies whatever files are on the card, so N-RAW, ProRes RAW and H.265 clips from a Z9 or Z8 are all copied and verified the same way. It works at the file level, regardless of codec.

What card reader do I need for a Nikon Z9 / Z8 card?

The Z9 and Z8 record to CFexpress Type B cards, so you need a CFexpress Type B reader (ideally USB 3.2 or faster) connected to your Mac. The Z8's second slot takes UHS-II SD, which a standard SD reader handles. Copsy reads any card your Mac can mount.

Can Copsy copy my Nikon footage to a drive and the cloud at once?

Yes. Copsy can copy your Nikon footage to an external drive and to Google Drive or Dropbox in parallel during the same offload, so your on-set backup and your cloud copy happen together.

When is it safe to format a Nikon card after offloading?

Only after Copsy reports that every file copied and passed ASC-MHL verification, and ideally only once you have at least two copies (for example, a drive plus a cloud copy). Then format the card in-camera rather than on the Mac.

Is Copsy free?

Yes, Copsy is free to download and use today, with no card limit and no account required. It runs on macOS 13 or later.

Back up your next Nikon card for free

Copsy is a free Mac camera-offload app. Verified copies of your Z9 / Z8 footage to a drive and the cloud, nothing lost.

⬇ Download Copsy for Mac

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