Converting a disc-based game from BIN/CUE to CHD can save space and turn a folder full of track files into one cleaner file. The conversion is also lossless, so a correctly created CHD can be extracted again later. The danger is not CHD itself. Problems usually begin with a damaged or incomplete CUE sheet, renamed track files, an unsupported emulator core, or deleting the source before testing the result.
This guide explains how to convert BIN/CUE games to CHD with MAME’s official chdman utility, verify the new file, preserve multi-track audio, handle multi-disc games, and avoid the mistakes that make a working dump appear broken.
What BIN, CUE, and CHD files contain
A BIN file stores raw disc data. A CUE file is a small text sheet that describes the disc layout: which BIN files belong to the disc, their order, track types, and index positions. Some games use one BIN file, while others have a data track plus many audio tracks.
CHD stands for Compressed Hunks of Data. It is a compressed container used by MAME and supported by many modern emulator cores. For CD images, it can preserve the disc’s data and audio track structure in a single file. That makes libraries easier to move and reduces wasted storage, especially on a microSD card used in a retro handheld.
CHD is not a universal replacement for every game format. Use it only for systems and emulator cores that explicitly support CHD. Cartridge ROMs such as NES or SNES files should not be converted with createcd.
Before you convert anything
Work from legally obtained disc images and keep an untouched backup. Conversion should begin only after the original BIN/CUE set already works in your emulator.
- Put the CUE and every referenced BIN file in the same working folder unless the CUE intentionally uses subfolders.
- Open the CUE in a plain-text editor and check every
FILEline. - Confirm that spelling, spaces, punctuation, and file extensions match the actual BIN filenames.
- Do not merge, rename, or delete audio tracks before conversion.
- Make sure the computer has enough free space for both the source and the new CHD.
- Keep another copy outside the working folder. Our backup and cloning guide explains why a single copy is not a reliable backup.
A CUE sheet may look simple, but it is the map that lets chdman reconstruct the disc correctly. Always supply the CUE as the input. Pointing the tool at one BIN from a multi-track set can omit other tracks and break music or later parts of the game.
Get chdman from a trusted source
chdman is distributed with MAME. Download the current package from the official MAME project rather than an unknown converter website or repackaged executable. Extract the package and locate chdman.exe on Windows or the corresponding chdman binary on your platform.
For the simplest workflow, copy the tool into a temporary working folder with one game’s CUE and BIN files. Advanced users can add its location to the system path, but that is not required.
Convert BIN/CUE to CHD with one command
Open Command Prompt, PowerShell, Terminal, or your preferred shell in the working folder. Then run:
chdman createcd --input "Game Name.cue" --output "Game Name.chd"In Windows PowerShell, use .\chdman.exe instead of chdman when the executable is in the current folder and not on your PATH. Apply this prefix to the later verify, info, and extract commands too. On Unix-like systems, a local executable may need ./chdman.
The shorter option names are equivalent:
chdman createcd -i "Game Name.cue" -o "Game Name.chd"Keep quotation marks around filenames that contain spaces. Replace the example names with the exact name of your CUE file and the desired output name. Do not add the --force option unless you deliberately want to overwrite an existing output file.
During conversion, chdman reads the CUE sheet, follows every referenced track, compresses the disc data, and writes one CHD. Completion without an error is a good sign, but it is not the final proof that the game is safe to delete from its original format.
Verify the BIN/CUE to CHD conversion
MAME documents a dedicated integrity check for read-only CHD files. Run:
chdman verify --input "Game Name.chd"You can also inspect the file’s format, compression, sizes, and hashes:
chdman info --input "Game Name.chd"A successful verification confirms that the CHD is internally consistent. It does not prove that the original dump was good, that the CUE described every track correctly, or that your chosen emulator supports the file. You still need a real gameplay test.
Test the game in the same emulator core
Copy the CHD to a separate test folder or the correct games folder on your device. Launch it with the same emulator or RetroArch core that previously ran the BIN/CUE version.
Do more than reach the title screen. Check the opening sequence, play long enough to trigger music and loading from later disc areas, and test a save if the game supports one. For multi-track games, listen for CD audio. A game can boot from its first data track even when later audio tracks were missing from a faulty source set.
If RetroArch does not list the new file, confirm that the core supports .chd, rescan or manually add the content, and update any playlist entry that still points to the old CUE. Our guide to RetroArch cores, playlists, and settings explains how those parts relate.
Special case: PlayStation SBI files
Some PAL PlayStation games with LibCrypt protection need an external SBI file in compatible cores such as Beetle PSX. The official Libretro documentation warns that SBI data is not integrated into the CHD during conversion.
Keep the required .sbi file beside the resulting CHD and follow the naming requirements of your emulator core. Do not discard it just because the BIN and CUE were replaced by one CHD. If a protected game booted before conversion but shows a warning or fails afterward, the missing or mismatched SBI file is one of the first things to check.
Convert multi-disc games correctly
Convert each disc separately. A two-disc game should produce two CHD files, not one combined CHD:
chdman createcd -i "Game (Disc 1).cue" -o "Game (Disc 1).chd"
chdman createcd -i "Game (Disc 2).cue" -o "Game (Disc 2).chd"Then update the M3U playlist so each line points to the new CHD filename:
Game (Disc 1).chd
Game (Disc 2).chdKeep the M3U and all listed CHDs together unless your paths are written intentionally. Our complete guide to multi-disc games, M3U files, and disc swapping covers playlist naming and RetroArch’s Disc Control menu.
Common BIN/CUE to CHD problems
chdman cannot find a BIN file
Open the CUE and compare its FILE entries with the real filenames. Fix the CUE or restore the expected names. On case-sensitive systems, Track 02.bin and track 02.bin are different names.
The command cannot find chdman
Run the terminal from the folder containing the tool or enter the full path to the executable. On some Unix-like systems, a binary in the current folder may need to be invoked as ./chdman.
The CHD verifies but the game does not launch
Check whether that exact emulator core supports CHD for the system. Try the original CUE again. If both formats fail, the problem is probably the source dump, BIOS, core, or configuration rather than compression. If only the CHD fails, update the emulator or test a current compatible core before converting the library in bulk.
Music or later levels are missing
This usually points to an incomplete source set or a CUE that did not reference every track. Restore the untouched files, repair the CUE based on the actual dump, and create the CHD again. Never invent track timing values.
Paths with unusual characters fail
Use quotation marks and try a short local working path with simple letters and numbers. Avoid converting directly on a network share, cloud-synced directory, or read-only card while troubleshooting.
How to extract a CHD again
Because the CD conversion is lossless, chdman can extract a CD CHD back to a CUE and BIN:
chdman extractcd --input "Game Name.chd" --output "Game Name.cue" --outputbin "Game Name.bin"The --splitbin option is available when separate output BIN files are needed. Extraction is useful for compatibility testing or rebuilding another archival format, but it is still wise to preserve the original verified source and its accompanying files.
When is it safe to delete the BIN/CUE files?
A BIN/CUE to CHD job is complete only after the new file has passed every practical check. Delete the working copy only after all of these checks pass:
chdman verifycompletes successfully.- The CHD launches in the intended emulator core.
- Gameplay, loading, and CD audio have been tested.
- Multi-disc M3U entries point to the new CHD filenames.
- Required SBI files remain available.
- An independent backup of the original or a proven recovery copy exists.
CHD is an excellent format for supported disc-based systems because it combines tidy storage with lossless compression. The safest workflow is simple: validate the CUE, convert with the official tool, verify the output, test it in the real core, and keep a backup until the new library has proven reliable.
