CUE File Documentation

Summary

A CUE (Cue Sheet) file is a tiny plain-text index that describes how a larger file is split into tracks; it contains no audio or disc data itself. Two cases are common: an audio cue that splits one big album file (FLAC/APE/WAV) into songs, and a BIN/CUE pair that together form a disc image. Open the matching media file in foobar2000 or VLC to play tracks, or mount the BIN with the .cue beside it. You can read or edit the cue in any text editor.

Technical details

FeatureValue
Full nameCue sheet (CUE index file)
File extension.cue
MIME typeapplication/x-cue
Format typePlain-text track/index descriptor (companion file)
OriginGoldenhawk CDRWIN, mid-1990s (de-facto convention)
Open standardPartial — a widely-followed convention, not a formal spec
EncodingUTF-8 / ASCII text; no binary signature
ContainsFILE reference, TRACK entries, INDEX timecodes, titles
Contains noAudio samples or disc sectors (index only)
Timecode formatMM:SS:FF (75 frames per second)
Audio companionA single FLAC/APE/WAV/WavPack album file
Disc-image companionA .bin raw sector image (BIN/CUE pair)
Audio toolsfoobar2000, CUETools, XLD, shnsplit
Disc-image toolsAnyBurn, PowerISO, IsoBuster
Related extensions.bin, .iso, .flac, .ape, .wav, .wv
Specificationen.wikipedia.org/wiki/Cue_sheet_(computing)
Syntax at a glance

A cue sheet is plain UTF-8/ASCII text with no file signature. It starts with optional REM comments (GENRE, DATE) and a FILE "name" <type> line naming the data file it indexes (WAVE for audio, BINARY for a .bin). Each song or track is a TRACK nn <mode> block (AUDIO, or MODE1/2352 for data), with a TITLE, PERFORMER and an INDEX 01 MM:SS:FF start time measured in minutes:seconds:frames at 75 frames per second. Identify a cue by these keywords, not by magic bytes.

What is a CUE file?

A CUE sheet (.cue) is a plain-text index file that tells software how to interpret a separate, much larger file. It stores nothing on its own: no audio, no disc sectors, only metadata. It records which data file it refers to, how many tracks that file contains, where each track starts, and the titles and performers. The convention comes from Goldenhawk’s CDRWIN burning software in the mid-1990s and was adopted broadly by rippers, players and burning tools.

One format covers two everyday uses. An audio cue accompanies a single gapless album file (one FLAC, APE, WAV or WavPack for a whole disc) and marks where each song begins, so a player can show and seek individual tracks or a splitter can cut them into separate files. A disc-image cue is half of a BIN/CUE pair: the .bin holds the raw disc sectors and the .cue describes the track layout. The rest of this page explains the cue’s commands and how the two cases differ.

The command structure: FILE, TRACK, INDEX

A cue sheet is a short list of commands, one per line, forming a shallow hierarchy: a FILE names the data file, each TRACK belongs to that file, and each track’s INDEX lines mark its position. Here is a typical audio cue for a two-track album:

REM GENRE Jazz
REM DATE 1959
PERFORMER "Artist Name"
TITLE "Album Name"
FILE "album.flac" WAVE
  TRACK 01 AUDIO
    TITLE "First Song"
    PERFORMER "Artist Name"
    INDEX 01 00:00:00
  TRACK 02 AUDIO
    TITLE "Second Song"
    INDEX 00 05:12:40      # pregap start
    INDEX 01 05:14:15      # track start (the audible beginning)

The FILE "album.flac" WAVE line names the single audio file this sheet indexes and its type. Each TRACK 01 AUDIO opens a track and declares its mode. The INDEX 01 line is the important one: it gives the track’s start time, and a player uses these times to present one big file as separate songs. An optional INDEX 00 marks a pregap (the silent gap before a track) so that the boundary between the previous track and this one is described precisely.

INDEX timecodes: MM:SS:FF at 75 frames per second

Every INDEX time is written as MM:SS:FF, minutes, seconds and frames. The frame is a Red Book CD-audio unit: there are exactly 75 frames per second, so the frame field runs from 0 to 74. A time of 05:14:15 therefore means 5 minutes, 14 seconds and 15/75 of a second. This 75-frames-per-second grid comes from the CD standard, where one frame is the smallest addressable block of audio (a sector holds 2,352 bytes of audio). Because the timing is expressed in these exact frame units, a cue can pinpoint a track boundary to a single CD sector, which is what makes gapless splitting sample-accurate.

Audio cue versus BIN/CUE disc image

The same commands describe two different companions, and the FILE type plus the TRACK mode tell them apart:

Audio cueBIN/CUE disc image
FILE typeWAVE (points at FLAC/APE/WAV)BINARY (points at a .bin)
TRACK modeAUDIOMODE1/2352, MODE2/2352 (data), or AUDIO
What it isAn album split into songsA raw optical-disc image
What you doPlay or split into per-track filesMount, burn, or convert to ISO

In the audio case, the cue turns one lossless album file into a track list you can play or split. In the disc-image case, the .bin is a byte-for-byte copy of the disc’s sectors and the cue describes the track layout, including data and audio tracks, their modes and pregaps. In both cases the two files must keep the same base name and stay in the same folder, because the cue points at its data file by name.

Splitting audio and converting disc images

For an audio cue, splitting the album into per-track files uses the cue’s INDEX points as cut markers. CUETools (Windows), XLD (Mac) and the shnsplit/cuetools combination (Linux) all do this:

cuebreakpoints album.cue | shnsplit -o flac album.flac

The cuebreakpoints command reads the INDEX times, and shnsplit cuts the single FLAC at those points into separate track files, carrying titles across as tags. For a BIN/CUE disc image, the usual task is converting the pair to a single ISO that Windows mounts natively; AnyBurn or PowerISO read the cue and output an .iso. One caveat: an ISO cannot hold CD-audio tracks, so a BIN/CUE that contains audio tracks will not convert cleanly to ISO and should stay as BIN/CUE.

Why a cue “won't open” and how to fix it

Because the cue references its data file by name in the FILE line, the most common failure is not corruption but a broken reference. If the audio or .bin file is renamed, moved, or has a different extension than the cue expects, the player or burner reports that the file cannot be found. The fix is to open the cue in any text editor and edit the FILE "..." line so it matches the real filename sitting next to it. Keeping the cue and its data file together with matching base names avoids the problem entirely. This editability is a direct consequence of the cue being plain text: it can be repaired by hand, which a binary index could not.

Frequently asked questions

Does a .cue file contain the music?

No. A cue is a small text index that describes how a separate, larger file is split into tracks. The actual audio or data lives in the file it points to (a FLAC/APE/WAV album, or a .bin). Open that file, with the cue beside it.

How do I open a .cue file to play an album?

Open the cue (not the audio file) in foobar2000, VLC or Cog with the matching FLAC/APE/WAV in the same folder; the player reads the cue and lists each song. To read the cue itself, open it in any text editor.

How do I split a single album file into separate songs using the cue?

Use CUETools (Windows), XLD (Mac) or shnsplit with cuetools (Linux). Give it the cue and the album file, and it cuts per-track FLAC or MP3 at the cue’s INDEX points, carrying titles across as tags.

My .cue won't open or says “file not found”. How do I fix it?

The FILE line points to a renamed or missing media file. Open the cue in a text editor and edit the FILE "..." line to match the real audio or .bin filename in the same folder. Keep the cue and its data file together with matching base names.

References