Connect your game

mk8u.de's 3D view shows courses, ghosts and races. The original graphics, intro flight, karts, drivers and music are part of Mario Kart 8 – these files belong to Nintendo, so mk8u.de does not hand them out. Instead your browser builds them from your own copy of the game.

The game files stay on your device. Nothing of them is uploaded to mk8u.de.
What is built stays stored in your browser. After that you only need your game for courses not built yet.
Without a connected game the 3D view shows the course as a plain surface and the racers as dots.

You connect it in the 3D view with the "Your game" button (controller icon) or by choosing "Course: original graphics".

Option 1: Straight from the Wii U (with the plugin)

Easiest if you use the mk8logger plugin (v0.40.00 or newer). The Wii U hands the running game's files to your browser in your home network.

Start Mario Kart 8 on the Wii U.
In the game, open the Aroma menu (L + D-Pad Down + SELECT) → Mario Kart 8 Logger.
Switch on "Share game files with mk8u.de (home network)" and close the menu. A notice with the address and code stays in the top left until mk8u.de has connected, e.g. address 192.168.0.20, code 482913 (the next time you open the menu they are also shown below the switch).
On mk8u.de: 3D view → Your game → Straight from the Wii U: enter address and code → Connect.
A small window of the Wii U opens. Keep it open while building.

Notes:

Device and Wii U must be in the same network (same Wi-Fi/router).
Allow pop-ups for mk8u.de if your browser blocks the window.
The code is new each time you switch it on. Sharing ends when you switch it off or quit the game. Without the code the Wii U gives nothing, and it only ever gives game files.
The first build takes a little longer over the network (a course some seconds, all karts up to a few minutes).

Option 2: Cemu file (.wua)

If you play Mario Kart 8 with Cemu and have your game as a .wua (best with update and DLC in it):

3D view → Your game → Cemu file (.wua) → Choose .wua file.
Pick the file – done.

Chrome and Edge remember the file; next time a click on "Allow the game files chosen last again" is enough. Other browsers ask again when a course not built yet is needed.

Option 3: Dump folder

A folder with the game's content folder somewhere inside:

Dumpling (Wii U homebrew): dump game, update and DLC; on the SD card they are under wiiu/dumps/…. Copy them to your computer.
Cemu: the folder mlc01/usr/title (with 00050000/1010ec00, 0005000e/1010ec00, 0005000c/1010ec00 in it – other numbers for other regions).

Then: 3D view → Your game → Dump folder → Choose folder and pick the top folder. Game, update and DLC may lie side by side; the update wins over the base game.

iPhone and iPad cannot pick folders – use the .wua or the Wii U there.

What happens with the data?

The browser reads only the files it needs for the course, the karts or the music you want, and builds 3D models, textures and sounds from them.
The result is stored in this browser on this device (IndexedDB). On another device or browser, connect your game there again.
A course takes about 7–16 MB, all karts about 90 MB, a piece of music about 10–20 MB.
Delete: in the "Your game" dialog → Delete stored courses, or via your browser's site data.

Allow persistent storage

Without permission a browser may delete the stored courses again, e.g. when storage runs low – then you have to connect your game again and everything is built anew. So after the first build mk8u.de asks for persistent storage:

Firefox asks: "Allow mk8u.de to store data in persistent storage?" → Allow. If you declined: lock icon in the address bar → Permissions → Store data in persistent storage → tick "Allow".
Chrome and Edge do not ask but decide themselves – usually yes for sites you visit often, bookmarked or installed as an app (mk8u.de can be installed via the browser menu, Install app).
Safari (iPhone, iPad, Mac) deletes site data when you do not visit mk8u.de for 7 days. Fix: add mk8u.de via Share → Add to Home Screen and open it from there.
Private / incognito window: everything is gone when the window closes.

Wii U GamePad as controller

When you drive yourself in the 3D view you can use the Wii U GamePad as controller – buttons, sticks and steering by tilting like in the game (full lock at 26°). This needs the plugin v0.42.00 or newer.

Switch on "Share game files with mk8u.de (home network)" as above (Mario Kart 8 running, best left in the main menu).
On mk8u.de: 3D view → Drive → row Wii U GamePad: enter address and code → Connect.
A small window of the Wii U opens; it shows the buttons pressed and the tilt. Keep it open (it may lie behind the browser).
The controls switch to "Tilt the Wii U GamePad". Rather steer with the stick? Choose keyboard/controller – the GamePad counts there like any controller.

While the GamePad controls mk8u.de, Mario Kart 8 ignores it (a notice says so in the top left). The plugin menu (L + D-pad down + SELECT) still works. With Disconnect, when the small window closes or when you leave the mk8u.de page, the game gets the GamePad back.

Which version?

Most complete with the update (v4.2) and all DLC. Without DLC the DLC courses and karts are missing; without the update some karts and course changes. All regions (EU, US, JP) work.

Problems?

Message / problem	Fix
"These are not Mario Kart 8 files"	Pick the folder with `content` (with `course` and `data` in it), or a folder above it.
"No answer from the Wii U"	Is MK8 running with plugin v0.40.00 or newer? Is sharing on? Are address and code right? Same network?
The Wii U window says "The code is wrong"	Use the code shown in the menu now – it changes each time you switch sharing on.
A course does not load	Open the "Your game" dialog and check it is still connected; pick the source again if needed.