How to Format a Memory Card in Your Camera

Short answer: Copy everything you need off the card first, then format it in the camera you will shoot with, not on a computer. Formatting erases the whole card. Sony, Canon, Nikon and Panasonic all tell you to format in the camera; the steps below use each maker's own menu names, taken from one example model's official manual.

Menu names can differ between models and firmware versions. If your camera's menu does not match, follow its own manual.

1. Back up before you format

Every maker warns that formatting cannot be undone:

• Sony: "formatting permanently erases all data on the memory card, and is unrecoverable. Save valuable data on a computer, etc."
• Canon: "When the card is formatted, all images and data on the card will be erased. Even protected images will be erased".
• Nikon: "formatting permanently deletes all pictures and other data on the card. Before formatting, be sure to make backup copies as required."
• Fujifilm: "All data—including protected pictures—will be deleted from the memory card. Be sure important files have been copied to a computer or other storage device."
• Panasonic: "Save a backup of necessary data before formatting the card."

Copy the files, open a few on the computer to check they copied correctly, then format.

Back up and check your files before you format: formatting cannot be undone.

2. Why format in the camera

• Sony: "Memory card formatted with a computer is not guaranteed to operate with the product. Be sure to format the memory card using this product."
• Canon: "If the card is new or was previously formatted (initialized) by another camera or computer, format the card with this camera."
• Nikon: "Memory cards that have been formatted in a computer or another camera should be reformatted using this option before use."
• Panasonic: "If the card has been formatted with a PC or other device, format it again with the camera."

A card formatted on a computer or another camera should be reformatted in the camera before use.

3. Step by step, by brand

Sony (example: α7SIII Help Guide)

1. MENU → (Shooting) → [Media] → [Format] → choose the memory card slot.
2. Select [Enter] for quick formatting.
3. For full formatting, press the Delete button when the message appears, then select [Enter].

Sony: "Perform full formatting when you feel like the speed of recording to the memory card or read-out from the memory card has become slow, or when you want to erase data completely".

Canon (example: EOS R5 Mark II manual)

1. In the setup menu, select [Format card].
2. Select the card (card 1 or card 2).
3. Select [OK]. For a low-level format, add a checkmark to [Low level format] first, then select [OK].

Canon: "Perform low-level formatting if the card's writing or reading speed seems slow or if you want to totally erase the data on the card."

Nikon (example: Z8 Reference Guide)

1. In the setup menu, select [Format Memory Card].
2. Choose a memory card slot and select [Yes].

Nikon notes that holding both format buttons "for over two seconds displays a dialog prompting you to select a card for formatting", and that CFexpress cards compatible with full format can be fully formatted to "delete data from all areas of the card".

Fujifilm (example: X-H2S manual)

1. In the SET UP tab, select USER SETTING > FORMAT.
2. Highlight the slot with the card and press MENU/OK.
3. Highlight OK and press MENU/OK.

Fujifilm: "Do not open the battery-chamber cover during formatting."

Panasonic (example: LUMIX S1RII manual)

1. In the [Setup] menu ([Card/File]), select [Card Format].
2. Choose [Card Slot 1(CFexpress)] or [Card Slot 2(SD)] and select [Yes].
3. For a low-level format of a CFexpress card, press [DISP.] to check [Low Level Format] before selecting [Yes].

Panasonic: "If the writing speed of the card has started to drop, we recommend performing a low level format."

4. While the camera is formatting

• Sony: "Do not remove the memory card while the access lamp is lit."
• Nikon: "Do not turn the camera off or remove memory cards until the message [Formatting memory card.] clears from the display."
• Panasonic: "Do not turn off the camera or perform another operation during formatting."

While formatting: keep the card in, keep the camera on, and wait for the message to clear.

5. Related products

CFexpress Type A and Type B cards carry a 5-year limited warranty; other products carry 180 days. See our Warranty Policy.

• CFexpress Type A Memory Card - PCIe 4.0 — for cameras and readers with a CFexpress Type A slot
• CFexpress Type A Memory Card - PCIe 3.0 — for cameras and readers with a CFexpress Type A slot
• CFexpress Type B Memory Card - PCIe 3.0 x2 — for cameras and readers with a CFexpress Type B slot
• CFexpress Type B Professional Memory Card - PCIe NVMe — for cameras and readers with a CFexpress Type B slot

Which cameras take which card? See CFexpress Type A compatible cameras, CFexpress Type B compatible cameras and CFexpress Type A vs Type B vs SD.

Sources (accessed 2026-10-30)

• Sony ILCE-7SM3 Help Guide, Format: https://helpguide.sony.net/ilc/2410/v1/en/contents/0601_memory_format.html
• Sony ILCE-7SM3 Help Guide, Notes on memory card: https://helpguide.sony.net/ilc/2410/v1/en/contents/1001C_notes_on_memory_card.html
• Canon EOS R5 Mark II manual, Card Formatting: https://cam.start.canon/en/C017/manual/html/UG-07_Set-up_0080.html
• Nikon Z8 Reference Guide, Format Memory Card: https://onlinemanual.nikonimglib.com/z8/en/sum_format_memory_card_315.html
• Fujifilm X-H2S manual, User Setting (Format): https://fujifilm-dsc.com/en/manual/x-h2s/menu_setup/user_setting/
• Panasonic DC-S1RM2 manual, [Setup] Menu: https://eww.pavc.panasonic.co.jp/dscoi/DC-S1RM2/html/DC-S1RM2_DVQP3245_eng/0130.html