A CUE file is a small text file that describes the track layout of a disc image. It contains no disc data itself. Instead, it tells mounting and burning tools which data file to use, what kind of tracks it holds, and where each track starts. If you have a BIN file, the CUE file is usually its companion, and understanding the CUE is the key to understanding why the pair works together.
This matters for WinBin2Iso users because the role of the CUE file is often misunderstood. For a data disc, WinBin2Iso does not need the CUE file to convert BIN to ISO. For mounting or burning the original BIN, the CUE is essential. Knowing which situation you are in saves time and prevents the common mistake of deleting a file you still need. You can get the converter from the WinBin2Iso download page.
What a CUE file actually contains
A CUE file is plain text. You can open it in Notepad or any text editor and read it. It does not contain audio, video, or program data. It contains lines that name a data file, declare track types, and give index positions. The data file named in the CUE, usually a BIN file, holds the actual disc contents. The CUE is the map; the BIN is the territory. Without the map, some tools cannot navigate the territory correctly, even though all the data is still present in the BIN.
Anatomy: FILE, TRACK, and INDEX
Three kinds of lines do most of the work in a CUE file. The FILE line names the data file and its type. The TRACK line declares a track and its mode. The INDEX line gives a position within that track, expressed in minutes, seconds, and frames. Together, they let a tool reconstruct the disc layout from the raw data.
Below is a generic example for a single data track. It is labelled as an example only, and it is not taken from any particular disc. Your own CUE file will name your own BIN file and may have different track details.
FILE “example.bin” BINARY
TRACK 1 MODE1/2352
INDEX 01 00:00:00
In this example, the FILE line points to a file called example.bin and says it is binary data. The TRACK line says track 1 is a MODE1 track with 2,352-byte raw sectors, which matches the raw sector size SoftwareOK describes for CDs. The INDEX line says the track starts at zero minutes, zero seconds, zero frames. A real disc with several tracks would have additional TRACK and INDEX lines, one set per track, in order.
Pairing rules: how BIN and CUE belong together
The pairing rules are simple, but they are worth stating plainly. First, the filename in the FILE line must match the actual BIN filename exactly, including spelling and, on systems that care about case, capitalisation. Second, the CUE and BIN should stay in the same folder, because many tools look for the data file relative to the CUE file. Third, do not rename one without updating the other. If you rename the BIN, open the CUE in a text editor and change the FILE line to match, then save it as plain text.
Fourth, a CUE file does not make a BIN file valid on its own. If the BIN is incomplete, truncated, or from a different disc, a correct-looking CUE will not fix it. The CUE describes layout; it cannot repair missing data. If a tool reports a CUE error, check the filename match and folder first, then consider whether the BIN itself is complete. Our guide to a missing or wrong CUE file walks through the common error messages and fixes.
When WinBin2Iso needs a CUE file, and when it does not
For a data disc, WinBin2Iso does not need the CUE file. You select the BIN file, choose an output ISO, and convert. The data is in the BIN, and for a data disc that is enough. This is good news if your CUE file is missing but your BIN is a data disc, because conversion can still proceed. Our tutorial on how to convert BIN to ISO without a CUE file covers that situation step by step.
For mounting or burning the original BIN, the CUE is a different story. Mounting tools and burning tools use the CUE to understand track boundaries and layout. Without it, they may refuse to mount the image, mount only part of it, or misread the track structure. The same applies to audio discs in general: even if a conversion tool does not ask for a CUE, the track information the CUE carries is what makes an audio disc behave like separate tracks rather than one long recording.
The practical rule is therefore: keep the CUE file whenever you have one, even when WinBin2Iso does not ask for it. It costs almost no disk space, and it preserves your options. If you later decide to mount or burn the original instead of using the ISO, you will be glad the CUE is still there.
Frequently asked questions
Can I open a CUE file to check it?
Yes. Open it in Notepad or another plain-text editor. You should see FILE, TRACK, and INDEX lines. If you see garbled characters instead, the file may have been saved in the wrong encoding or may not be a CUE file at all.
Do I need to keep the CUE after converting to ISO?
Keep it until you are sure you no longer need the original. It is tiny, and it lets you mount or burn the original BIN later. For audio discs, keep the BIN and CUE pair as the primary copy.