How to Convert GameCube/Wii ISO to RVZ — Dolphin's Compressed Format 2026

What RVZ is: RVZ is Dolphin's native compressed disc image format (introduced in Dolphin 5.0-12188, 2021). It uses Zstandard compression and stores raw-data blocks separately from game data to prevent corruption, making it Dolphin's recommended format for archiving GameCube and Wii games. A typical GameCube ISO (1.4 GB) compresses to ~600–900 MB as RVZ; a 4.7 GB Wii ISO usually becomes 1.5–3 GB depending on content.

Convert from inside Dolphin (the easiest method):

1. Add the folder containing your ISOs to Dolphin's game list: Settings → Paths → Add.
2. In the game list, right-click the game you want to convert.
3. Select "Convert File…" from the context menu.
4. In the conversion dialog:
   • Format: RVZ
   • Compression: Zstd (recommended — best balance of speed and ratio)
   • Compression Level: 5 (default; increase to 9 for smaller files at the cost of slower conversion)
5. Choose an output folder and click Start Conversion. Dolphin creates the .rvz file alongside the original.
6. Once done, verify the game launches from the .rvz in your game list. If it works, delete the original .iso to free space.

Dolphin loads .rvz files the same as .iso files. No special settings or plugins needed — Dolphin decompresses on the fly with no measurable performance impact on modern hardware.

For converting many files at once, use DolphinTool, the command-line companion bundled with Dolphin.

Find DolphinTool:

• Windows: in the same folder as Dolphin.exe, look for DolphinTool.exe.
• Linux: usually /usr/bin/dolphin-tool or alongside the Dolphin AppImage.
• Mac: inside the Dolphin.app bundle at Contents/MacOS/DolphinTool.

Convert a single file:

• DolphinTool convert -f rvz -c zstd -l 5 -i "game.iso" -o "game.rvz"

Batch convert all ISOs in a folder (Windows Command Prompt):

• for %f in (C:\Games\*.iso) do DolphinTool.exe convert -f rvz -c zstd -l 5 -i "%f" -o "%~dpnf.rvz"

This converts every .iso in C:\Games\ to an .rvz in the same folder. Verify a few files launch in Dolphin before deleting all the originals.

Verify an RVZ file is intact:

• DolphinTool verify -i "game.rvz" — prints a hash and confirms the file is uncorrupted.

Format comparison for Dolphin:

• RVZ (recommended, 2021+): Dolphin's current preferred format. Zstd compression, raw-block safety, fast decompression, full Dolphin support. Use this for new archives.
• GCZ (legacy): Dolphin's older compressed format. Still works fine in Dolphin but has a known corruption risk on "junk data" blocks (common in some Wii ISOs). If you have GCZ files from years ago, re-convert to RVZ for long-term safety.
• WBFS: a Wii USB-loader format (used by Wii Backup Manager / FAT partition layout). Dolphin can read WBFS but it's not a compression format — file sizes are similar to ISO. WBFS is for USB loading on real Wii hardware; for Dolphin use RVZ instead.
• ISO / GCM: raw disc image, no compression. Largest files. Keep one uncompressed ISO as your source if you do ROM hacking; use RVZ for all emulation copies.
• WIA: an older compressed format (Windows Image Archive), now superseded by RVZ. If you have WIA files, Dolphin can read them and you can convert them to RVZ via the same right-click method.

Does RVZ work in other emulators? RVZ is Dolphin-specific. RetroArch's Dolphin core and the Dolphin Android app support RVZ. Other GameCube/Wii frontends (Ishiiruka, SlippiDolphin) support it as well since they share Dolphin's codebase. Non-Dolphin-derived programs cannot read RVZ — if you need the file in another tool, convert back to ISO first.

"Convert File" option is greyed out / not in the right-click menu:

• This happens when the game file is in a format Dolphin can read but not re-export (e.g., encrypted WUP/NUS format). Confirm the game is a standard .iso or .gcm.
• Older Dolphin versions (pre-5.0-12188) do not have RVZ support. Update to the current Dolphin stable release from dolphin-emu.org.

Converted .rvz file is the same size as the ISO: GameCube ISOs contain large "junk data" padding regions. Dolphin's converter scrubs junk data before compressing, which is why conversion takes longer than a simple file compress. If the RVZ is still large, the game data itself is just dense (Wii sports titles, for example, compress poorly). This is normal — the conversion is still valid.

Game launches from ISO but crashes from RVZ:

• Run DolphinTool verify -i "game.rvz" to check for corruption. If it fails, reconvert from the original ISO.
• If verify passes but the game crashes at a specific point, the source ISO may have bad sectors. Verify the ISO's hash against a trusted database (Redump) before converting.
• Updating Dolphin to the latest stable release fixes known RVZ decompression edge-cases that affected some early 5.0-121xx builds.

WBFS → RVZ conversion: Dolphin can read WBFS directly. Open the WBFS file in Dolphin's game list (add the folder), right-click → Convert → RVZ. The output will be a standard Wii game RVZ — no need to convert WBFS to ISO first.