How to Cut a Sample or Loop From a Song
To cut a sample or loop from a song, open a free audio cutter, find the downbeat on the waveform, set your selection to exactly one or two bars at the song's tempo, and export the slice. The whole thing takes a couple of minutes once you know the tempo, and because everything runs in your browser, your audio never leaves your device. The only real skill is making the chunk loop, which is where a sample differs from an ordinary trim.
A loop isn't just a trim
Trimming a clip for a message or a social post asks one thing of you: pick a start and an end you like. A loop asks more. It has to seam — the moment the end meets the start again has to land in rhythm, with no hiccup, no gap, and no click, because you're going to hear that join over and over.
So two things have to be true at once. The length of your selection has to equal a whole number of musical bars, so the pulse stays even when it repeats. And the cut points themselves have to be clean, so the join doesn't pop. Get the length wrong and the loop drifts or stutters; get the cut points wrong and it clicks. The rest of this guide is really about those two problems.
What you'll need
- A song file you already own — MP3, WAV, or similar. The cutter works on a file on your device; there's no URL-pasting or stream-ripping involved.
- The song's tempo (BPM). You'll use it to set the loop length. If you don't know it, grab it first (see the tempo section below).
- A rough idea of which bar you want. The drum fill, the piano stab, the two bars of bassline — know the moment before you start slicing.
Step by step
- Load the song. Drop the file onto the audio cutter or click to select it. It decodes locally and draws an interactive waveform in the Audio Cutter Workspace — no upload, no account.
- Find the downbeat. Look at the waveform for the loud, evenly spaced spikes; those transients are usually your kick or snare hits. The downbeat is the "one" of a bar, the pulse you'd count off first. Pick a clear transient to start on, because cutting on the downbeat is what makes the loop feel intentional rather than random.
- Set the start. Drag the Trim Start point slider so it sits right on that downbeat. The readout shows time to a tenth of a second (for example
00:04.2), which is close enough to land on the beat by eye. - Set the length to one or two bars. Watch the Selection duration readout — it shows something like
00:02.0 selected out of 03:24.0. Move the Trim End point until that duration matches one bar (or two) at the song's tempo. The math is in the next section. - Preview the seam. Hit Play Selection. It plays your chosen range once and stops. Listen to how it ends, then hit play again and imagine the end wrapping straight back to the start. Does the pulse stay even? Any gap of silence, or a beat that arrives too soon or too late?
- Refine by ear. Nudge the start or end slider a tenth of a second at a time and re-preview until the loop feels tight. You position with the slider, but the actual cut is sample-accurate — it slices on exact sample offsets, not rounded to the tenth you see — so small ear-guided adjustments really do land where you want them.
- Export. Choose your format: WAV (lossless, the safe default for dropping into a DAW), MP3, or Opus. Click Cut & Download and the file saves with a
cut_prefix. Close Track resets if you want to grab another slice.
One honest note up front: the cutter has no tempo grid, no beat markers, and no snap-to-transient. It won't magnetize your selection to the beat for you. You find the downbeat and the loop length yourself, by eye on the waveform, by ear with Play Selection, and with the tenth-of-a-second readout. That's more hands-on, but it's the same workflow hardware samplers have used for decades.
Match the loop length to the tempo
This is the part that makes a loop actually loop. In 4/4 time — which covers the vast majority of pop, hip-hop, house, and rock — one bar is four beats, and each beat lasts 60 ÷ BPM seconds. So one bar lasts:
One bar = 240 ÷ BPM seconds.
Take a track at 120 BPM. 240 ÷ 120 = 2.0 seconds per bar, so you'd set the Selection duration to 00:02.0 for a one-bar loop, or 00:04.0 for two bars. A few common tempos:
| Tempo | One bar | Two bars |
|---|---|---|
| 90 BPM | ≈ 2.67 s | ≈ 5.33 s |
| 120 BPM | 2.00 s | 4.00 s |
| 140 BPM | ≈ 1.71 s | ≈ 3.43 s |
The order of operations is: get the BPM first, then set the length. If you don't already know the tempo, drop the song into the BPM finder — it's a two-second job — or read the full walkthrough on how to find the BPM of any song. Then dial the Selection duration to your target bar length.
Because the sliders move in 0.1-second steps, you'll land close to the exact bar rather than dead on it: 2.67 seconds rounds to 00:02.7, not the true 2.667. That's fine. Set the length as near as the readout allows, then fine-tune the seam by ear with Play Selection. Landing close and finishing by ear is precisely how real samplers work, because the ear is the final judge, not the number.
Cut cleanly so the loop doesn't click
Even a perfectly timed loop pops if you cut in the wrong spot. A click happens when the waveform is partway through a wave at the cut point, and that sudden jump in level is an audible tick. The fix is to cut where the waveform crosses the zero line (the quiet moment between waves), and to start and end on transients rather than in the middle of a sustained note. At the slider's tenth-of-a-second resolution you won't be targeting an exact zero sample by hand, so treat this as an ear job: nudge until the tick is gone. The full detail on why it works, and how to cut audio without losing quality, covers zero crossings properly — worth a read if your slices keep ticking.
In practice, Play Selection is your seam test. Preview, adjust a tenth of a second, preview again. If you hear a tick at the loop point, walk the start or end slightly until it disappears. A loop that's rhythmically correct but clicks at the join is a cut-point problem, not a timing one.
Sampling one instrument instead of the whole mix
Sometimes you don't want the full track, you want just the drums, or just the bassline, with none of the vocal bleeding over your loop. Do that separation first, then cut. Run the track through a stem splitter to split the song into stems, export the part you want, and load that into the cutter. Now your one-bar loop is a clean isolated instrument with nothing fighting it in the mix — far easier to seam, and far more usable underneath your own beat.
A quick, honest word on copyright
Cutting a loop from a record you love is a great way to learn. Releasing it is a different matter: sampling a copyrighted recording for anything you publish or sell generally needs the rights holder's clearance, no matter how short the clip. Before a sampled track goes public, read up on copyright and fair use when sampling so you know where you stand. For practice, learning, and royalty-free source material, you're on far safer ground.
Troubleshooting
- The loop has a gap or a stutter. Your selection length isn't a whole number of bars. Recheck the tempo, recompute
240 ÷ BPM, and reset the Selection duration to match. A length that's slightly short leaves a silent gap; slightly long makes the next hit arrive early. - It clicks at the seam. That's a cut-point problem, not a timing one. Nudge the start or end a tenth of a second so the cut lands on a zero crossing or a transient, and re-test with Play Selection until the tick is gone.
- The loop feels off even though the length is right. You probably started on the wrong beat, the "two" or the "and" instead of the downbeat. Move the Trim Start to the nearest strong, evenly spaced transient and try again.
- The loop drifts out of time in my DAW. The exported length doesn't quite equal the bar length your project expects. Confirm your DAW tempo matches the song's BPM, and re-cut as close to the exact bar length as the readout allows; a hair of drift compounds over many repeats.
What to do next
Once you've got a clean loop, it's raw material. Layer a few isolated stems back together to make a remix using stems, or fit two tracks together to make a mashup from two songs. And when you want the next technique, the full library of audio how-to guides has the rest of the workflow covered.
Frequently asked questions
How long should a sample loop be? Usually one or two bars. In 4/4 time, one bar lasts 240 ÷ BPM seconds — so 2.0 seconds at 120 BPM, about 1.71 seconds at 140. Set your Selection duration to that length. One bar is tight and repetitive; two bars give a phrase more room to breathe before it repeats.
What BPM is my sample? It's the tempo of the song you're cutting from, which you should find before you slice. Drop the track into a BPM finder to read it in about a second, then use it to calculate your bar length. Getting the tempo first is what lets the loop repeat evenly instead of drifting.
Why does my loop click or stutter? A click means you cut mid-waveform, so move the start or end a fraction until it lands on a zero crossing. A stutter or gap means the length isn't a whole number of bars, so recompute 240 ÷ BPM and reset the Selection duration. Use Play Selection to test the seam after every nudge.
Can I sample any song I want? For practice and learning, cut freely. For anything you release or sell, sampling a copyrighted recording generally needs clearance from the rights holder, even for a one-bar loop. Check the copyright and fair-use guidance before publishing, and lean on royalty-free source material when you can.
Do I need a DAW to loop a sample? No. The audio cutter runs entirely in your browser: load a file, set a one-bar or two-bar selection, preview the seam, and export a WAV or MP3. A DAW helps once you're arranging loops into a full beat, but for cutting the slice itself, the browser tool is all you need, and your audio never leaves your device.