Nasu is a spritesheet and nametable editor created to help us design and assemble the assets of our famicom games. It can import and export both .chr spritesheets and .asm nametables. If you wish to learn more about creating 8bit projects, see our Assembly Guide.


Meet Nasubit, the mascot for Nasu. Nasubit is there to talk about updates relating to Nasu.

sprite editor

The viewport is divided into 3 regions, the Sprite Editor, the Tile Selector and the Nametable Editor. The Sprite Editor allows you to see 16 tiles at once, and paint sprites in 4 colors. You can navigate the sprite editor with the wasd keys, and you can change the brush color with the number keys(1 to 4).

tile selector

The Tile Selector shows you 512 sprites, or 256 sprites per page. To toggle between the two pages in memory, use the tab key, and to move the selected tile, use the arrow keys.

nametable editor

The Nametable Editor shows you the full arrangement of 32x30 sprites. Select a sprite in the Tile Selector and click on the nametable editor to paint it.


We create our own tools, built light to reduce our energy use, also to lessen our dependence on closed-source applications we can't repair ourselves. Nasu works in the browser. It is bundled as a single file of 52kb, runs offline and has no dependencies.

The reason we did this, is because we want to ensure that users — us included — have access to these tools no matter what. We want our ecosystem of tools to be...

Read more about our design philosophy


web version

If you don't wish to download the build(43kb), and if you have access to a reliable internet connection, you can use Nasu in your browser.

Use Nasu Live


If you find a bug or would like to suggest an improvement, open an issue.