Which Output ISO Format Should I Choose in WBFS to ISO?

Updated

Choose Wii game ISO if the converted file is meant to be burned to a disc and played on a Wii console — it is the default and produces a 1:1 disc copy of about 4.37 GB. Choose CISO if you mainly want to save space, since the output stays close to the source file's size. Choose ISO 9660 only when the file needs to be opened by other software on a computer and will never be used on a Wii. The format is selected in the "ISO Format" options before you start the conversion.

The three formats at a glance

Format Size What it is for Works on a Wii after burning?
Wii game ISO About 4.37 GB (1:1 disc copy) Burning to disc and playing on Wii hardware Yes
CISO (Compact ISO) Almost the same as the source file Keeping a smaller converted copy Not stated on the site
ISO 9660 Not stated Opening the file with most other software on a PC No — the site explicitly says burned discs will not work on a Wii

The site only describes the Wii-compatibility outcome for Wii game ISO and ISO 9660. It does not say whether a burned CISO disc plays on a Wii, so treat CISO as a space-saving option rather than a confirmed disc format.

How the choice plays out in practice

The WBFS file itself is a dump of a single Wii partition and usually holds one game, though the format can hold several. The conversion does not change what the game is — it changes the container, and the container decides what you can do with the result.

  • Playing on original hardware: pick Wii game ISO. The site notes this format "cannot be opened directly on the computer" and must be burned to disc before it can be played on a Wii. That is the intended path, not a limitation to work around.
  • Archiving or moving files around: pick CISO. Because the output is roughly the size of the WBFS source, you avoid inflating a compressed file into a 4.37 GB image you may not need.
  • Inspecting or sharing the contents on a PC: pick ISO 9660. It is readable by most other software, which makes it convenient for desktop use — but the same convenience is exactly why it fails on Wii hardware.

A concrete case: if you have a 4 GB WBFS file and only want to check that the conversion succeeded before committing to a disc, converting to CISO keeps the footprint small; converting to Wii game ISO gives you the burn-ready image but costs the full 4.37 GB.

Step by step

  1. Click Open and select the *.wbfs file you want to convert.
  2. Click Select and choose the output folder.
  3. Open the ISO Format options and pick Wii game ISO, CISO, or ISO 9660 according to the table above.
  4. Click Convert. The software writes the *.iso file to the folder you chose.

If you skip step 3, the output is Wii game ISO — the default.

Common sticking points

  • The result won't open on your computer. That is expected for Wii game ISO; it is built for burning, not for desktop playback. If you need to open it on a PC, convert again with ISO 9660.
  • The disc doesn't run on the Wii. Check that you did not convert to ISO 9660. The site states plainly that discs burned from that format cannot be used on the Wii machine.
  • The output is much larger than the source. That is the normal cost of a 1:1 Wii game ISO. Use CISO if size matters more than burn-readiness.
  • You are unsure which format a file already is. The extension alone won't tell you; re-run the conversion with the format you actually need rather than guessing.

The tool is described on its own site as small, free software for Wii game fans, and the page carries a copyright notice covering 2011–2025. Wii is a trademark of Nintendo Inc.; the site is not affiliated with Nintendo.