Multiplatform disc image processor & deduplicated game storage
Convert, extract, scan, verify, fix, and deduplicate disc images across 14 gaming systems.
Then store your entire collection at ~80% space savings with instant virtual-drive mounting.

NKit is a free, multiplatform disc image processor written in C#/.NET (native AOT compiled). It reads and writes 15+ disc image formats, processes images directly from archives without extraction, and provides scanning, verification, conversion, extraction, fixing, and deduplication — all in one tool.

NKit started nearly 10 years ago as a GameCube/Wii recovery tool. NKit 2 is a full rewrite encompassing all the functionality of dozens of scattered community tools into one unified, cross-platform toolkit.

Four applications ship together:

All binaries are native AOT executables — no .NET runtime required. Download, run, done.

NKDS is a deduplicated game-storage and archiving format. It understands what's inside disc images — not just raw bytes — and uses that knowledge for massive space savings.

Watch the NKDS introduction video

Storage costs money. A full Wii set is 16 TB. Compressed to RVZ that's still ~6 TB. NKDS stores it in under 3 TB — an 83% reduction.

This isn't better compression. It's filesystem-level deduplication — shared system updates, engine libraries, and textures stored once instead of thousands of times, across your entire collection.

• ~80% space savings — Deduplication + Zstandard compression
• Mountable virtual drive — Emulators see regular ISOs, no extraction needed (Dokan/FUSE)
• Byte-perfect reconstruction — Every image verifiable, no data loss
• Crash-safe — Dual-header atomic commits, automatic recovery from power loss
• Flexible storage — Single-file (portable per-game) or multi-file (scalable to hundreds of TB)
• Any source format — ISO, RVZ, WBFS, WUX, CHD, archives — NKDS reads them all
• Multiple workflows — Use nkds / nkds-ui directly, or use NKit's dedupe task (nkit -task dedupe) to create and populate NKDS sets
• Folder storage — Store non-disc content too (MAME sets, versioned ROM collections)
• Export on demand — Reconstruct to any format (ISO, RVZ, WUX, CSO...) directly from the store

Reads: ISO, RVZ, WIA, WBFS, CISO, WUD, WUX, GCZ, CHD, CSO, ZSO, DAX, JSO, CUE+BIN, GDI, NKit (legacy), CDN/APP, XISO

Writes: ISO, RVZ (Zstandard/LZMA), WBFS, CISO, WUX, CSO, ZSO, APP, CUE, GDI

Process images directly from archives — no temp files, no extraction to disk:

• RAR (1–5) — split, multi-volume, solid
• ZIP / ZipX — split, multi-volume, Zstandard/XZ compression
• 7-Zip — split, solid, Zstandard
• GZip — split

• Convert — Between any readable/writable format pair, lossless or lossy
• Extract — Pull files from disc images with wildcard/regex masks
• Scan — Generate container-independent XML fingerprints
• Verify — Multiple fallback methods (checksums, dat matching, scan comparison)
• Fix — Repair modified images (unscrub, restore partitions, rebuild from IRD)
• Dedupe — Deduplicate to NKDS DataStore

Releases are published to this repository. Check the Releases page for the latest builds.

The source is here: github.com/Nanook/NKit. Nearly 10 years of development, now open.

Bug reports and feature requests: open a GitHub Issue.
Contributions: see Contributing in the wiki.

Q: When will the source code be released? It's public now — you're looking at it.

Q: Can I contribute? Yes. See Contributing for how to build, test, and submit a PR.

Q: Where do I report bugs? GitHub Issues is the primary channel. Discord is good for questions and discussion.

Q: Is this free? Yes, always. NKit and NKDS are a hobby and a gift to the communities I enjoy being part of. If you'd like to support the work, you can buy me a beer or sponsor me.

Q: Does NKDS support all systems? The DataStore (add/mount/export) currently supports GameCube, Wii, and Wii U. More systems are coming. NKit itself (convert, extract, scan, verify) already supports all 14 systems.

Q: Do I need to install .NET? No. All releases are native AOT binaries — fully self-contained.

Q: Where do I report bugs? GitHub Issues is the primary channel. Discord is good for questions and discussion.

Q: What about NKit 1 / the old nkit.iso format? NKit 2 reads the legacy nkit.iso/nkit.gcz format but no longer writes it. RVZ replaced it as the recommended compressed format. Use NKit 2 to convert your old nkit files to RVZ.

MIT — see LICENSE.

_{NKit & NKDS by Nanook — nearly 10 years of late-night development for game preservation.}