Compress Nintendo 3DS ROMs to Z3DS in the browser

Compress Nintendo 3DS ROMs to Z3DS, ZCCI, ZCXI, ZCIA, or Z3DSX locally in your browser. Files stay on your device.

Add the Nintendo 3DS file

1. Open Compress.
2. Add one .3ds, .cci, .cxi, .cia, .3dsx, or .app file to Inputs.
3. Remove other files before choosing the output format.

For a ROM inside ZIP, 7z, or an existing compressed 3DS file, add that file to Compress. Select the ROM, then select the Add button.

Create the compressed file

1. In Output, choose Z3DS.
2. Enter the output filename without its extension.
3. Keep the default compression level, or open Options to change it.
4. Select Compress and wait for the result.
5. Select Download and save the compressed file.

The Z3DS option covers every supported 3DS subtype. For example, a .cia input produces .zcia, while .3dsx produces .z3dsx.

Keep the extension assigned by Compress. The Z3DS filename reference lists each mapping.

If Z3DS is unavailable, check the input extension and keep only one file in Inputs. Changing an extension does not convert the contents.

Check the result

Test the compressed file in an emulator that supports its Z3DS subtype. Keep the original until you check the result.

To check the uncompressed bytes, extract the compressed file. Compare its checksum with the original through Identify.

Keep enough free storage for the original and compressed output. Compression does not decrypt a ROM or convert a CIA package into a cartridge image.

Choosing a compression format explains Z3DS compatibility. For GameCube and Wii discs, use ISO to RVZ.