Audio Splitter
Cut a long recording into tracks or parts, without re-encoding MP3 and AAC.
Try before you buy.
- Free preview: every part listed with its times, and the first parts (up to 3) as their first half, up to 30 seconds each, with a short MySmartCoPilot chime.
- Locked until you unlock it: download.
- Unlock: Pro pass, ₹179 for 30 days or ₹79 for 1 week, a one-time payment that never renews. Unlock: Pro pass, $5.99 for 30 days or $2.99 for 1 week, a one-time payment that never renews.
Ways to unlock shows how to get the full result.
Printing this result is locked in the free preview.
How to split
m:ss or h:mm:ss, for example 30:00 for half-hour parts. A last part shorter than a quarter of that joins the one before.
Paste a YouTube description, a Bandcamp or Discogs tracklist, or chapter times: each line needs a time like 3:15 or 1:02:03.
Tracks start at their INDEX 01 time (minutes:seconds:frames, 75 frames a second).
Waveform
The waveform needs the whole recording decoded once; for At silences this happens by itself.
Parts
| # | Name | Start | End | Length |
|---|
Names become the file names and the title tags; you can change them here.
Save the parts as
What will happen
—
Parts
Locked in the free preview. Opens the ways to unlock this result.
Locked in the free preview. Batch runs unlock with a pass.
Locked in the free preview. Query results unlock with a pass.
About the Audio Splitter
Cut a long recording — an audiobook, a lecture, a podcast, a DJ mix or a whole album — into separate files. Split it into N equal parts, into parts of a fixed length, at its silences, at the times of a tracklist you paste (a YouTube description, a Bandcamp or Discogs list, chapter times), or by a CUE sheet, with each track’s name.
MP3 and AAC (M4A, M4B) are split without re-encoding: the original frames are copied, so nothing is lost and it is quick; the cuts land on the nearest frame, a few hundredths of a second away. WAV and FLAC are cut sample for sample. You can also turn the parts into MP3, M4A, WAV or FLAC. Each part gets its title, the album, the artist and a track number in its tags, and the parts download one by one or as one ZIP. Everything runs in your browser; nothing is uploaded.
Without a pass, the result is a free preview: every part listed, and the first parts as short previews with a MySmartCoPilot chime.
How to use it
- Drop a recording on the box or click Choose a recording.
- Choose how to split it: Equal parts, Fixed length, At silences (set how quiet and how long a silence is), Tracklist (paste one line per track) or CUE sheet (choose the .cue file or paste it).
- Check the Parts table and change any name; choose the format (Same as the original copies MP3 and AAC unchanged) and the album and artist for the tags.
- Press Split. With a pass, or after unlocking this split, Download each part or Download all (ZIP). Without a pass the page lists every part and plays a free preview of the first ones — the first half of each, up to 30 seconds, with a short MySmartCoPilot chime — and Ways to unlock shows how to get the files.
Examples
book.m4b · 9:45:10 · Fixed length 30:00
20 files from “book - part 01 of 20.m4a”, the AAC frames copied unchanged; the last part is 15:10
mix.mp3 · tracklist “00:00 Intro / 04:12 First track / 1:02:30 Last track”
“01 - Intro.mp3”, “02 - First track.mp3” … with titles and track numbers in their tags
album.flac + album.cue (12 tracks, INDEX 01 times)
12 FLAC files named after the tracks, cut sample for sample, with the album and performer from the sheet
The five ways to split
- Equal parts: N parts of the same length.
- Fixed length: parts of 10, 30 or 60 minutes (or any length); a last part shorter than a quarter of that is added to the one before.
- At silences: the whole recording is read once, and it is cut in the middle of every pause that is quieter than your level (−45 dB by default) for at least your time (1.5 s by default), never leaving a part shorter than your shortest part. Good for lectures, talks and recordings of separate songs.
- Tracklist: one track per line, with a time such as
3:15or1:02:03anywhere on it; track numbers and dashes around the time are dropped from the name. The page tells start times from track lengths (lengths of an album that add up to the recording), or you choose. - CUE sheet: each track starts at its
INDEX 01time, written as minutes:seconds:frames with 75 frames a second; a pregap (INDEX 00) stays at the end of the track before. With severalFILEs in one sheet, the tracks of the file with the recording’s name are used.
Without re-encoding
An MP3 or AAC file is a row of small frames, about 20 to 26 milliseconds each at the usual sample rates of 44.1 and 48 kHz. Same as the original copies whole frames into each part, so the sound is bit for bit the original, and each cut is the frame boundary nearest to the time you asked for. Other codecs (Opus, Vorbis, AC-3) cannot be cut unchanged here, so they are written as MP3 unless you choose another format. WAV and FLAC are decoded and written again with the same samples, so no sound is lost either.
Limitations
- Silence detection and the waveform need the whole recording decoded once, which takes a while for a many-hour file, and they need a browser that can decode its codec.
- Chapters stored inside an M4B or MP3 file are not read; paste their times as a tracklist instead.
- Up to 300 parts at once. Very long recordings (several hours of WAV) need a lot of memory to keep every part until it is downloaded.
- Old formats such as WMA and RealAudio cannot be read in the browser.
Privacy
On this device: nothing is sent
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
What do I get without a pass?
Without a pass, Audio Splitter shows every part listed with its times, and the first parts (up to 3) as their first half, up to 30 seconds each, with a short MySmartCoPilot chime. Until you unlock it, the result can’t be downloaded. A Pro, Premium or Ultimate pass, a one-time payment that never renews, unlocks the full result. The pricing page lists the passes and their prices.
Do I need a pass?
To download the parts, yes: a Pro pass unlocks every Pro tool. Without a pass you see a free preview of your own split: every part listed with its times and name, and the first parts (up to 3) playing the first half of each, up to 30 seconds, with a short MySmartCoPilot chime. An unlock of this one split (Ways to unlock lists how) makes every part from the file still open on the page.
Does splitting lower the quality?
Not with Same as the original for MP3, AAC, WAV and FLAC: MP3 and AAC frames are copied unchanged and WAV and FLAC samples are written exactly as they were. Choosing another format encodes the parts again.
Why is a cut a little away from the time I typed?
An MP3 or AAC part without re-encoding can only start at a frame boundary, so each cut moves to the nearest one, at most half a frame away: about 13 milliseconds for a 44.1 kHz MP3. Choose WAV or FLAC for cuts on the exact sample.
What should a tracklist look like?
One track per line with its start time, for example 00:00 Intro, 03:15 - First song or [1:02:03] Finale. Lines without a time are skipped. If your list gives each track’s length instead (as album listings do), the page notices when they add up to the recording, or choose How long each track is.
Is my recording uploaded?
No. The file is read and split inside your browser, and the parts are saved to your device.
Open-source components
This page can load these open-source components, each only when a task needs it:
- It uses FFmpeg under the LGPLv2.1 and the LAME MP3 encoder under the LGPL, through libav.js: licence and source code.
- It uses FFmpeg under the LGPLv2.1, through the Mediabunny add-ons: licence and source code.
- It uses the LAME MP3 encoder under the LGPL, through the Mediabunny MP3 add-on: licence and source code.
- It uses Mediabunny under the MPL 2.0: licence and source code.
You may replace them with your own builds. Their licences and the credits of every library the site uses are on the open-source credits page.