What a .mii file is and why you'd export one

A .mii file is a data file that stores the appearance of a Mii character — the customizable avatar you create on Nintendo systems. When you export a .mii file, you're saving that character's look (face shape, hair, eyes, mouth, skin tone, and clothing) as a single file you can move between devices, share with others, or back up for safekeeping.

You might export a .mii file if you want to use the same character on a different Nintendo console, send your Mii to a friend, or keep a copy before deleting it from your system. The file itself is small — usually just a few kilobytes — and contains only the visual information, not any game progress or account data.

Key Takeaways

  • On Nintendo Switch, you export a Mii by opening the Mii Studio app, selecting your character, and choosing the export option from the menu.
  • The exported file saves to your Switch's microSD card as a .mii file that you can copy to a computer or send to another person.
  • On Wii and Wii U, the process is similar but accessed through the Mii Channel or Mii Maker app instead.
  • Once exported, you can import that same .mii file onto any other Nintendo Switch, Wii, or Wii U console.

Exporting a Mii on Nintendo Switch

Open the Mii Studio app from your Switch home screen. Select the Mii character you want to export by tapping on it. Once the character is open, look for a menu button (usually three horizontal lines or dots in the corner) and select the export or save option.

The Switch will save the file to your microSD card. If you don't have a microSD card installed, you won't be able to export. The file will have a .mii extension and a name you can customize. From there, you can remove the microSD card, insert it into a computer, and copy the .mii file to your computer's storage or email it to someone else.

Exporting a Mii on Wii or Wii U

On the original Wii, open the Mii Channel from the home screen. Select the Mii you want to export, then choose "Copy" from the options menu. This copies the character to an external storage device (like an SD card on Wii U) rather than creating a separate file you can see.

On Wii U, the process is similar but accessed through the Mii Maker app. Select your character, then look for an export or copy option in the menu. The exported Mii can then be transferred to another Wii U console or, in some cases, to a Switch using the Mii Studio app's import feature.

Moving a .mii file to your computer

To get a .mii file from your Switch to a computer, you need a microSD card reader. Remove the microSD card from your Switch (power it off first), insert it into a card reader connected to your computer, and navigate to the folder where Mii files are stored. On Switch, this is usually in a folder labeled "Nintendo" or "Miis."

Once you locate the .mii file, you can copy it to any folder on your computer just like any other file. From there, you can email it, upload it to cloud storage, or keep it as a backup. The file is small enough that it won't take up meaningful space on your computer.

Importing a .mii file onto another console

To use an exported .mii file on a different Switch, copy the file back onto a microSD card, insert that card into the new Switch, and open Mii Studio. Select the import option and choose the .mii file from your card. The character will appear in your Mii collection on that console.

If you're importing onto a Wii or Wii U, the process depends on which console you're using. Wii U can import from an SD card through Mii Maker. Original Wii consoles require the file to be on an SD card as well, and you'll use the Mii Channel to import it. Check your specific console's manual if you're unsure where the import option is located.

What happens when you export a Mii

Exporting a Mii does not delete it from your console — it creates a copy. Your original character stays in your Mii collection, and the exported file is a separate copy you can move or share. If you delete the Mii from your console later, the exported file remains wherever you saved it.

The .mii file contains only the character's appearance data. It does not include any game progress, achievements, or account information tied to that Mii. If you import the Mii onto another console, it will look identical but will start fresh with no game history.

Sharing a .mii file with others

Once you've exported a .mii file to your computer, you can email it to a friend or upload it to a file-sharing service like Google Drive or Dropbox. Your friend can then read the file, copy it to their microSD card, and import it into their own Switch or other Nintendo console.

Some Nintendo communities and forums also have sections where people share .mii files. You can post your exported file there for others to read and use. There's no risk to sharing a .mii file — it's just appearance data and contains no personal information or account details.

Frequently Asked Questions

Can I export a Mii without a microSD card?

No. On Nintendo Switch, you need a microSD card to export Mii files. The Switch's internal storage doesn't have a way to save .mii files directly. If you don't have a card, you'll need to purchase one before you can export.

What if I lose my .mii file after exporting it?

If you still have the Mii on your console, you can export it again. If you've deleted the Mii from your console and lost the exported file, the character is gone unless you remember exactly how it looked and recreate it manually in Mii Studio.

Can I edit a .mii file after exporting it?

No. The .mii file itself is not editable as text or code. To change the character's appearance, you must import the file back into a console, edit the Mii in Mii Studio, and then export it again as a new file.

Will my Mii look the same on every console?

Yes. When you export and import a .mii file, the character's appearance remains identical across all consoles. The only thing that changes is the console and any game progress associated with that Mii on each system.

Can I convert a .mii file to another format?

Not easily. The .mii format is proprietary to Nintendo systems. Some third-party tools exist online that claim to convert .mii files to images or other formats, but these are not official and may not work reliably. Your best option is to keep the file in its original .mii format.