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Waveform generator.
A waveform you can read.
Split into bass, mid and top the way a CDJ draws it, so the picture shows the arrangement rather than a rectangle. A bar grid over the top, the breakdown and the drop marked, and a transparent PNG at up to three thousand pixels when you want it for artwork.
Drop a track and get its waveform
WAV, AIFF, FLAC, MP3 or M4A. Drop several and they queue. Nothing is uploaded — this page makes no network request at all.
Why every other one looks the same
The rectangle problem.
A plain amplitude waveform made sense when tracks had dynamics. Mastering removed them, and the picture stopped carrying information about ten years before anyone noticed.
Put two club tracks side by side as plain waveforms and you will struggle to tell them apart. Both are a solid block from the first bar to the last, because both were limited to within a decibel of full scale for their entire length — that is what mastering for a dancefloor means. The only feature that survives is the breakdown, and only if the breakdown is genuinely quieter rather than simply thinner.
Pioneer solved this on the CDJ screens years ago and the answer was not more resolution, it was colour. Split the signal at the crossover points a sound system uses and draw the three envelopes together, and the block becomes legible again: the low band drops out through a breakdown while the mids and top carry on, a riser shows as the top band climbing on its own, and the drop is the moment the bass returns at full height. None of that is visible in the outline, because the outline never changed.
So that is the default here, at 200 Hz and 2 kHz, with two cascaded filters on each crossover so the bands genuinely separate rather than bleeding into each other. Every band is scaled by the same factor, always — the ratio between them is the information, and normalising them individually would look prettier and mean nothing.
Three bands, because one is a rectangle
Every track released in the last twenty years is limited flat, so a plain amplitude waveform of a club track is a block with a small notch in it — and every plain waveform of every club track looks the same. That is why the CDJ screens, Rekordbox and Serato all split theirs by frequency. The signal is run through two crossovers at 200 Hz and 2 kHz, the same places a rig divides it, and the three envelopes are drawn nested: bass underneath, mids over it, top over that. Suddenly the picture has information in it. A breakdown is where the purple leaves. A drop is where it comes back at full height. You can read the arrangement of a track you have never heard.
A grid in bars, not a ruler in seconds
The tempo is read off the file and the bar lines go over the top, with every sixteenth one brighter because sixteen bars is the phrase a track is built out of. That turns the picture from a timeline into a score: the intro is not "the first 38 seconds", it is 32 bars, which is the unit you would actually plan a mix in. The sections underneath name where the low end leaves and returns, snapped to the nearest bar, so an eyeball reading of the arrangement takes about a second.
An export that is a real render, not a screenshot
The download re-runs the drawing at the size you asked for against a 4,096-column read of the audio, so a 3000-pixel PNG has 3000 pixels of genuine detail in it rather than an upscale of whatever your browser window happened to be. Four palettes, including a black-on-white one that prints and a blue-and-orange one that will look familiar to anyone who has stared at a CDJ. Transparent background if it is going over artwork. The grid and the section labels are optional and the labels never burn into the image.
Where the grid comes from
The bar lines need a tempo, and the tempo is read off the file rather than typed in. Checked against 300 tracks whose tempo was already set by the people who released them — someone else’s answer rather than our own, which is the only way the comparison means anything.
84.3%
Within ±2 BPM
88.7%
Within ±2, either octave
98%
Confident enough to draw
10.2%
Of drawn grids, wrong
The last figure is the one that describes the experience, because a grid is only drawn when the detector is confident enough to draw one. The octave column is not a hedge either: a lot of drum and bass ships tagged at half the tempo it is played at, so the detector and the tag can differ by exactly a factor of two with neither of them wrong.
Four styles
What each drawing is for
Which one to reach for is a question about the job, not about taste.
| Style | What it draws | When |
|---|---|---|
| Frequency bands | Bass, mid and top drawn nested in three colours. | Reading a track. This is the CDJ picture and it is the only one that shows you where the low end is, which is the whole point of looking. |
| Peak | A single-colour envelope of the loudest sample per column. | Artwork and banners, where you want the outline of the track rather than an analysis of it. |
| Peak + RMS | The peak outline with the average level filled in underneath. | Judging dynamics. The gap between the two is the crest factor — a wide gap is a track that breathes, a thin one is a track that was flattened. |
| Bars | Discrete columns with a gap between them. | Podcast and video artwork, and anywhere the waveform is a graphic rather than a measurement. |
Frequently asked
Common questions
Does my file get uploaded?+
No. Open the network panel before you drop a file and watch it stay empty — this page makes no request of any kind once it has loaded. The browser decodes the audio, JavaScript already in the page splits it into bands, and a canvas draws it. Nothing leaves the tab, which also means an unreleased dub or a promo is safe to drop on it.
Why is the waveform in three colours?+
Because a single-colour waveform of a modern track tells you almost nothing. Mastering pushes everything to the ceiling, so the outline is a rectangle whether the track is a peak-time roller or an ambient intro. Splitting it at 200 Hz and 2 kHz — the same crossovers a club rig uses — separates the kick and bass from the body and the top, and the ratio between them is the arrangement. It is what Rekordbox, Serato and the CDJ screens all do, and it is the reason a DJ can look at a waveform on a player and know where the drop is.
Can I get a transparent background?+
Yes — turn on the transparent PNG option and the export comes out with an alpha channel and no backdrop, so it drops straight onto artwork, a video, or a coloured banner. The on-screen preview still paints a background because you have to see it against something.
What size should I export?+
1600 × 300 for a web page or an email. 2480 × 520 for a SoundCloud banner, which is the size the platform asks for. 3000 × 800 for anything going to print or being cropped afterwards. All three are genuine renders at that resolution rather than a scaled screenshot, so the 3000 px one has detail the 1600 does not.
How accurate is the bar grid?+
Measured on 300 tracks whose tempo was already set by the people who released them: 84.3% within ±2 BPM, 88.7% once a half or double-time reading is allowed. The grid is only drawn when the detector is confident, which is 98% of files, and of the grids it does draw 10.2% are wrong. If you want the tempo on its own and want it sharper, the key and BPM finder runs a heavier detector — it has a couple of megabytes to download first, which is why a page that draws pictures does not use it.
How does it know where the breakdown is?+
By watching the bass. A club track is defined by whether the kick is playing, so the energy below 150 Hz is tracked across the file and the stretches where it falls under half its usual level are the breakdowns. The moment it comes back is the drop. The threshold is relative to the track's own median rather than an absolute level, so a quiet track and a loud one read the same, and every boundary is snapped to the nearest bar. It gets confused by tracks with no kick at all and by anything with a broken pattern, and the picture is the check.
Can I use the image commercially?+
The image is generated from your file on your machine and we make no claim on it whatsoever — use it on a release, a poster, a video, anything. Whether you have the right to use the underlying audio is between you and whoever owns it, which is the only part we cannot help with.
Why is my quiet track drawn full height?+
Because the drawing is scaled to the file's own peak, so a bounce that peaks at -12 dBFS still renders as a waveform rather than as a thin line down the middle. All three bands are scaled by the same factor, never separately — the ratio between them is the information, and scaling them independently would destroy it. The tool says when it has done this.
Will it handle a whole DJ set?+
Up to 800 MB, so a 75-minute 24-bit stereo recording is fine. The band split is a single pass over the samples and stays fast at that length; the tempo detection gets a coarser time step past about four minutes, which is honest — a single constant tempo across an hour-long set is the wrong model anyway, and the grid is the first thing to turn off on one.
Which formats can I drop on it?+
WAV, AIFF, FLAC, MP3, M4A, AAC, Ogg and Opus. The decoding is done by the browser, so Chrome and Edge read every format a DJ owns while Safari and Firefox refuse some AIFF and FLAC variants. If a file is rejected that is what happened, and converting it to WAV fixes it.
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