How to split an mp3 at specific timestamps
- Step 1Open the splitter and drop your MP3 — Go to the audio splitter and drop the MP3. It loads into memory in your browser and is never uploaded. One file per run.
- Step 2Set Split mode to Manual markers — Change the Split mode dropdown to Manual markers. The marker list appears with an Add marker button. (The other modes — Every N seconds and On silence — are for fixed-length and pause-based cuts respectively.)
- Step 3Convert your timestamps to seconds — Each marker is entered in seconds. Convert mm:ss by multiplying minutes by 60: 4:12 → 4×60+12 =
252; 9:48 →588; 15:30 →930. The field accepts one decimal place, so 4:12.5 is252.5. - Step 4Add a marker for each cut point — Click Add marker once per cut point and type its seconds value. You need one marker per boundary between regions — for N regions, add N−1 markers. Order doesn't matter; they're sorted automatically.
- Step 5Run the split — Start processing. FFmpeg cuts each region with
-ss <start> -t <length>and re-encodes it with libmp3lame. Markers at 0 or beyond the MP3's length are dropped, and any region under 0.05 s is skipped. - Step 6Download the regions — Click Download all to save each region as its own MP3, or Download per row for a single one. Files are named
<name>-part-1,<name>-part-2, in cut order. Rename to track titles afterward.
mm:ss to seconds quick reference
The marker field takes seconds (decimals to 0.1). Multiply minutes by 60 and add the seconds. Common conversions below.
| Timestamp (mm:ss) | Seconds | Timestamp (mm:ss) | Seconds |
|---|---|---|---|
| 1:00 | 60 | 10:00 | 600 |
| 2:30 | 150 | 15:30 | 930 |
| 4:12 | 252 | 25:00 | 1500 |
| 5:45 | 345 | 33:20 | 2000 |
| 9:48 | 588 | 60:00 | 3600 |
Markers vs regions
How many markers to add for the number of MP3 regions you want. Regions = markers + 1, because the file's start (0) and end are implicit boundaries.
| Regions wanted | Markers to add | Example marker positions (s) |
|---|---|---|
| 2 | 1 | 300 |
| 3 | 2 | 252, 588 |
| 4 | 3 | 252, 588, 930 |
| 5 | 4 | 150, 345, 588, 930 |
| N | N − 1 | your N−1 cut points |
What the timestamp split does and does not do
MP3-specific behaviour grounded in the tool. Use a sibling tool where a capability is not present.
| Question | Answer | Where instead |
|---|---|---|
| Lossless / stream-copy cut? | No — segments are re-encoded with libmp3lame | audio-trimmer lossless mode |
| Change output to WAV/FLAC? | No format selector — output stays MP3 | convert first, e.g. mp3-to-wav |
| Sub-second precision? | Yes — markers accept 0.1 s steps | — |
| Bundle as ZIP? | No — each region is a separate download | — |
Cookbook
Timestamp-driven MP3 splits. Marker positions are in seconds — convert mm:ss before entering. Output regions are separate MP3 files, re-encoded with libmp3lame.
Split a live set into tracks by setlist times
You have the track-boundary times from the setlist. Enter each boundary (in seconds) as a marker; each track becomes its own MP3.
Input: liveset.mp3 (62:00) Mode: Manual markers Boundaries: 4:12, 9:48, 15:30, 22:05, ... Add markers (s): 252, 588, 930, 1325, ... Result: (markers + 1) tracks liveset-part-1 ... liveset-part-N (each .mp3, re-encoded libmp3lame)
Extract one clip between two timestamps
Want only the 4:12-9:48 section as a standalone MP3? Add two markers and keep the middle region (part-2).
Mode: Manual markers Add marker: 252 (4:12) Add marker: 588 (9:48) Regions: 3 part-1: 0:00-4:12 part-2: 4:12-9:48 <- the clip you want part-3: 9:48-end Keep part-2; discard the rest.
Sub-second precision on a tight edit
The downbeat lands at 12:30.5, not 12:30. Markers accept one decimal, so enter 750.5.
Mode: Manual markers Add marker: 750.5 (12:30.5) Cut lands at 750.5 s, not 750. Useful when an MP3's keyframe-free cut needs to land exactly on a beat.
Enter markers out of order — they self-sort
Type boundaries as you remember them; the splitter orders them before cutting.
Add markers: 930, 252, 588 (any order) Splitter sorts -> 252, 588, 930 Regions: 0-252, 252-588, 588-930, 930-end (4 regions, correctly ordered)
Split, then rejoin selected regions
Cut the MP3 at known points, then merge the regions you want into one continuous file.
splitter (markers 252, 588, 930) -> 4 regions audio-merger (/audio-tools/audio-merger) -> drop part-1 + part-3 in order -> one MP3, parts 2 and 4 omitted
Edge cases and what actually happens
Entering a timestamp as mm:ss instead of seconds
Invalid inputThe marker field is a numeric seconds input, not a clock field — typing 4:12 will not parse as four minutes twelve seconds. Convert first: 4:12 is 252. The mm:ss-to-seconds table above covers the common values.
Marker placed at 0 or beyond the MP3's end
IgnoredThe splitter keeps only markers where 0 < position < duration. A marker at 0 (the file already starts there) or past the end is silently dropped, so it never produces an empty region. Check your region count if it's one less than expected — an out-of-range marker was discarded.
Two markers at (almost) the same time
Tiny region dropped if < 0.05 sTwo markers within 0.05 seconds of each other produce a region too short to write, which is skipped. Space markers by at least a fraction of a second if you intend a real region between them.
Expecting a byte-exact (lossless) MP3 cut
Re-encodedEach region is re-encoded with libmp3lame, so it is not a sample-for-sample copy of the source frames — there is one generation of lossy re-encode. For DJ-grade gapless or archival exactness, use the audio trimmer with its stream-copy lossless option (single cut at a time).
Wanting WAV or FLAC output from the split
Not supported hereThere is no output-format selector — MP3 in means MP3 out. To split into WAV or FLAC, convert the MP3 first with mp3-to-wav or mp3-to-flac, then split the converted file.
Want a single ZIP of all regions
Not supportedRegions download as separate files. Download all saves each one individually in a single click; there is no ZIP bundling. If multiple downloads are blocked, allow them for the site or use the per-row links.
Free tier user tries to split an MP3
Tier blockedThe splitter is Pro-tier. On Free the run is blocked. Pro handles MP3s up to 200 MB and 120 minutes — enough for a full DJ set; longer recordings need Pro-media (unlimited duration).
MP3 longer than your tier's duration limit
RejectedPro caps a single file at 120 minutes. A 3-hour live mix exceeds that and is rejected before processing — split on Pro-media/Developer (unlimited duration), or trim it down first with the audio trimmer.
Cut lands slightly off the intended beat
Use a decimal markerIf a whole-second marker clips just before or after a downbeat, nudge it with a decimal (e.g. 252.4). The marker field accepts 0.1 s steps, giving you finer placement than whole seconds.
Frequently asked questions
How do I split an MP3 at a specific timestamp?
Set Split mode to Manual markers, click Add marker, and enter the cut point in seconds (4:12 = 252). Add one marker per boundary; the MP3 is cut into markers + 1 regions, each a separate MP3 file.
Why won't it accept '4:12' in the marker field?
The field takes seconds, not clock time. Convert mm:ss to seconds first: 4:12 is 4×60+12 = 252. The conversion table above lists the common values, and the field accepts one decimal place for sub-second cuts.
Is the MP3 split lossless?
No. Each region is re-encoded with libmp3lame, so there is one generation of lossy re-encode. For a byte-exact, stream-copied cut, use the audio trimmer's lossless option (one cut at a time).
Does the output stay MP3?
Yes. The splitter has no format selector, so MP3 input produces MP3 output. If you need WAV or FLAC regions, convert the MP3 first with mp3-to-wav or mp3-to-flac and split the result.
How many regions do I get from my markers?
Markers + 1. The file start (0) and end are implicit boundaries, so three markers give four regions. The exact count appears in the result panel after the run.
Can I place cut points more precisely than whole seconds?
Yes — the marker field accepts 0.1 s steps. So 12:30.5 is 750.5. This is useful for landing a cut exactly on a beat in a music MP3.
Does it matter what order I add markers in?
No. The splitter sorts markers ascending before cutting, and ignores any at 0 or beyond the file's duration. Type them in whatever order is convenient.
Do I get a ZIP of the parts?
No — each region is a separate file. Download all saves them individually; per-row Download links grab a single region. There is no ZIP.
Is my MP3 uploaded?
No. FFmpeg 8.1 runs in your browser via WebAssembly. The MP3 stays on your device, so unreleased mixes and private recordings never leave your machine.
What's the longest MP3 I can split?
On Pro, up to 120 minutes and 200 MB. Pro-media and Developer lift the duration cap (100 GB file ceiling), which covers multi-hour DJ sets and live recordings.
Can I just extract one section between two timestamps?
Yes — add two markers (start and end of the section). You'll get three regions; keep the middle one (part-2). Alternatively, for a single clip the audio trimmer takes a start and end directly.
How do I recombine some of the regions?
Drop the regions you want into the audio merger in order; it concatenates them end-to-end into one MP3. Skip the regions you don't want.
Privacy first
Every JAD Audio tool runs entirely in your browser via FFmpeg (WebAssembly) and RNNoise. Your audio files never leave your device — verified by zero outbound network requests during processing.