Split an Audacity project at its labels
Drop a project that has a label track: every label is listed under the audio, free to download as Audacity's own label file or copy as timestamps. Then export one file per label — or one MP3 with a chapter at each — without opening Audacity.
An Audacity 1.x or 2.x project (.aup)? — the .aup and its _data folder together, or drop that folder or a .zip of it above.
Several projects? Drop or choose them together: export them all to one ZIP at once (Pro), or open them one by one free.
How do I split an Audacity project into separate files at its labels?
Drop the .aup3 or .aup4 on this page and choose Split at labels. Each label starts a file: a region label is cut at its own end, a point label runs to the next label, and the last point label runs to the end of the audio — the rule Audacity's Export Multiple uses. Files are numbered and named after the labels (01-Intro, 02-Verse…) and come as one ZIP. It all runs in your browser, with nothing uploaded, and the labels themselves can be downloaded free.
Drop the .aup4 or .aup3 — or an old .aup with its _data folder. It is read on your machine.
The label tracks appear under the audio and every label is listed; download them as a label file or copy them as timestamps, free.
Choose Split at labels for one file per label, or One MP3, a chapter per label.
Splitting and chapters are Pro; the stereo mix stays free up to 256 MB.
Split an Audacity project at its labels
Labels are how people mark the parts of a long recording in Audacity: songs on a digitised record, chapters of an audiobook, segments of a podcast, questions in an interview. Audacity can cut a project at them itself (File → Export Audio → Multiple files → Split files based on labels), but only where Audacity is installed, and it always uses the first label track in the project. This page reads the same labels straight from the project file, cuts the mix the way Audacity does, and lets you pick which label track to cut at.
On a Mac? Audacity's own recovery utility only gained a macOS build in January 2026, and it is still a terminal program that asks for about four times the project's size in free space. Everything on this page runs in the browser instead, on any operating system.
How Audacity stores labels, and where a split cuts
A label track is saved in the project document beside the audio tracks, as a <labeltrack> element with a numlabels attribute and one <label> child per label. Each label holds t and t1 — its start and end in seconds, the same value twice for a point label — and title, its text; Audacity 4.0 adds an isSelected flag. The labels are kept in time order. The document format is the same in .aup3 and .aup4, and an Audacity 2 .aup writes the same element and attribute names as plain XML, so all three are read the same way here.
Export Multiple in Audacity builds its list of files from the first label track only. Each label starts a file at its own start; the end is the label's own end when it is a region, the next label's start when it is a point, and the end of the project for the last point label. The audio before the first label becomes a file only when Include audio before first label is ticked, which is off by default. Files are named from the label text with a two-digit number in front, and an empty title becomes untitled.
The cut here follows those rules on the stereo mix, a window at a time, so each file holds exactly the samples of its span of the whole mix; MP3s get an ID3v2.3 tag with the label as their title. The chapter MP3 encodes the mix once and puts the chapters in front, as ID3 chapter frames rather than separate files.
- Element
- <labeltrack numlabels> with one <label t t1 title> per label
- Times
- Seconds as doubles; a point label has t1 equal to t
- Split rule
- Region: its own end · point: next label · last point: end of the audio
- Audio before the first label
- Its own file only when asked; off by default, as in Audacity
- Label track used
- Audacity: always the first · here: the one you pick
- Label file
- start⇥end⇥title per line, six digits after the point
- Chapters
- ID3 CHAP + CTOC, milliseconds, at most 255
New to the format? What an .aup4 file is, table by table — and how it differs from .aup3.
Sources
Where the facts on this page were checked. Audacity's code is cited at the tagged release it was read from.
- LabelTrack.cpp, Audacity 4.0.0 — WriteXML writes <labeltrack> with numlabels and, per label, t and t1 from the selected region, title and isSelected; LabelStruct::Export writes the TEXT label file as start, end and title separated by tabs, with FLT_DIG (six) digits after the point.
- LabelTrack.cpp, Audacity 3.7.9 — The same <labeltrack> and <label t t1 title> elements, without isSelected.
- ExportAudioDialog.cpp, Audacity 4.0.0 — UpdateLabelExportSettings takes the first label track; each file starts at a label, ends at the label's end for a region, at the next label's start for a point, or at the end of the tracks; IncludeAudioBeforeFirstLabel defaults to false; empty titles become "untitled" and numbered names are "%02d-" plus the title.
- ID3v2 Chapter Frame Addendum — CHAP holds an element id, start and end times in milliseconds and start and end byte offsets (all 0xFF = unused), then sub-frames such as TIT2; CTOC holds an element id, a flags byte (top-level, ordered), a one-byte entry count and the child element ids. An addendum to both ID3v2.3 and ID3v2.4.
Converting this file
Q. Where does each file start and end?
At the label's start. A region label (one with an end time) gives a file that ends where the region ends, so the audio between that region and the next label is in no file. A point label gives a file that runs to the next label's start; the last one runs to the end of the audio. The audio before the first label is left out unless you tick Include audio before the first label, which exports it as a file of its own named after the project. Those are the rules and the default of Audacity's own Split files based on labels.
Q. My project has more than one label track. Which one is used?
The one you pick. Audacity's own export always cuts at the first label track in the project, which is why a second track of notes or markers gets ignored there; here every label track is listed, and the split and the chapters use the one selected.
Q. What is in the MP3 with chapters?
The whole mix as one MP3, with an ID3 tag in front holding one chapter per label — a CHAP frame giving its title and its start and end in milliseconds — and a table of contents that lists them in order. Players that read ID3 chapters, as many podcast apps do, show and skip between them. A chapter table holds at most 255 entries, so a project with more labels gets chapters for the first 255 and is told so.
Q. Can I just get the labels out as text?
Yes, free, however large the project is. Labels (.txt) writes Audacity's own label file — start, end and title on each line, separated by tabs, times in seconds with six digits after the point — which Audacity's File → Import → Labels reads back into any project. Copy timestamps puts one "m:ss Title" line per label on the clipboard, the form show notes and video descriptions use.
Q. What are the files called?
A two-digit number, a hyphen and the label's text, as Audacity numbers them: 01-Intro.mp3, 02-Verse.mp3. Characters a file name cannot hold become an underscore, a label with no text is called untitled, and two labels with the same text get a (2) so nothing is overwritten. Each MP3 also carries the label as its title and its position as the track number.
Free to open, play and export the stereo mix for projects up to 256 MB; larger projects still open and play free, and downgrading to .aup3 is free up to the same size. Recovery, per-track stems, and exports or downgrades above that size are a one-time $19 license — no subscription, no recurring fees.
Every job an Audacity project needs
Same local-first engine, one page per task.