Convert MP3 to CUE

Some players, disc-authoring programs, and archive workflows require a CUE sheet to show the track boundaries inside a continuous MP3 album, mix, audiobook, or live recording. A CUE file can also provide a disc-style track list for separate MP3 files without changing the audio.

MP3 and CUE files

MP3 is a lossy compressed audio format used for music downloads, podcasts, voice recordings, portable players, and media libraries. It stores audio in a relatively small file, but a single MP3 can contain an entire album or long recording with no embedded track boundaries.

A CUE sheet is a plain-text file, usually named album.cue, that references audio files and defines tracks, titles, performers, and index positions. CUE creation does not convert or re-encode the MP3. The MP3 remains the audio source; the CUE file only supplies its track map.

For one continuous file, each INDEX 01 entry marks a track start as minutes:seconds:frames. CUE timing uses 75 frames per second, so its maximum timing resolution is 1/75 second. A CUE sheet can also reference several files, normally with one FILE section and one track beginning at 00:00:00 for each MP3.

Creating a CUE sheet from MP3 files

First identify the source layout. A continuous MP3 requires verified start times for every track; obtain the original CUE sheet when possible, or mark the starts manually. Separate MP3 tracks do not need timing calculations, but some players do not support multi-file CUE sheets consistently.

1. Put the MP3 file or files and the new .cue file in the same folder. Use the exact source filename in each FILE entry, including capitalization, spaces, and punctuation.
2. For a continuous MP3, use mp3DirectCut on Windows to audition the MP3 and place track boundaries without re-encoding it. Its cue-sheet functions can save or edit the track map. Audacity can also be used to locate starts and create labels, but its exported label text is not itself a CUE sheet.
3. Create or edit the CUE sheet in a text editor, mp3DirectCut, or foobar2000's cue-sheet editor. Enter each track title and its absolute start time within the continuous MP3.
4. Convert fractional seconds to CUE frames by multiplying by 75 and rounding to the nearest whole frame. For example, 3 minutes 42.50 seconds is approximately 03:42:38.
5. Save the file as plain text with a .cue extension. UTF-8 is suitable for current software; test non-ASCII names in older players, which may expect a local ANSI code page.
6. Open the CUE sheet in foobar2000 to confirm that all tracks appear, load, and begin at the intended positions.

For a single MP3 containing an album, use a structure like this:

PERFORMER "Artist"
TITLE "Album"
FILE "album.mp3" MP3
  TRACK 01 AUDIO
    TITLE "First track"
    INDEX 01 00:00:00
  TRACK 02 AUDIO
    TITLE "Second track"
    INDEX 01 03:42:38

For individually numbered MP3 files, use a separate FILE declaration for each source file:

FILE "01 - First track.mp3" MP3
  TRACK 01 AUDIO
    TITLE "First track"
    INDEX 01 00:00:00
FILE "02 - Second track.mp3" MP3
  TRACK 02 AUDIO
    TITLE "Second track"
    INDEX 01 00:00:00

The MP3 file type is supported by common CUE-aware applications such as foobar2000 and mp3DirectCut, but it is not accepted by every CUE consumer. Generic online converters are not useful for a continuous MP3 because they cannot reliably determine the intended musical boundaries. An online tool is only suitable when it lets you enter verified filenames, titles, and timestamps manually; verify its output locally before relying on it.

Quality and compatibility limits

Creating a CUE sheet causes no quality loss and no size reduction, because no audio data is changed. Renaming, moving, or deleting a referenced MP3 breaks the link until the FILE entry is corrected.

A CUE sheet cannot reliably infer track starts from silence. Silence detection is especially unreliable for live albums, DJ mixes, gapless albums, recordings with quiet intros, and tracks that overlap. Use an original cue sheet, verified timings, or manual listening rather than release track durations alone.

Some older CD-burning programs accept CUE sheets only when they reference PCM WAV files. If that program rejects FILE "album.mp3" MP3, decode the MP3 to WAV and make a CUE sheet for the WAV file; decoding does not restore MP3 quality and produces a much larger file. For an audio CD, the authoring software may require 44.1 kHz, 16-bit stereo PCM WAV.

MP3-backed CUE playback can vary by decoder, particularly with variable-bitrate MP3 files and encoder delay. CUE indexes are time-based rather than sample-accurate, so confirm transitions in the exact player or burner that will use the file.