OneTaskBy Tim King · Updated
Waveform from Video
Turn a Video's Soundtrack Into a PNG
OneTask is free, with no sign-up, and built by one person.
If this tool saved you time, a coffee helps keep new ones coming.
How the Waveform From Video works
This waveform from video tool decodes the soundtrack of a clip and draws it as a PNG image. Pick bars or a solid shape, a colour and a background, then download. It is handy for thumbnails, podcast art and spotting the loud and quiet parts of a recording. Nothing is uploaded.
A waveform is a picture of loudness over time. Peaks show speech, music and bangs; flat stretches show pauses and silence. Video editors draw one under every clip, but getting it out as an image for a thumbnail, a slide or a social post usually means screenshots and cropping.
How the waveform from video tool works
Your browser reads the whole file and decodes its audio track into raw samples with the Web Audio API, the same way it would decode an MP3. The picture is then split into columns. For each column the tool finds the loudest sample in that slice of time, taking the louder of the left and right channels, and draws a bar of that height above and below the centre line. The tallest peak is scaled to 95% of the image height, so quiet recordings still fill the frame.
Choosing a style
| Style | Looks like | Good for |
|---|---|---|
| Bars | Separate bars, 6 pixels apart | Podcast clips, music posts, thumbnails |
| Solid | One continuous shape, a column per pixel | Editing references, detail on long clips |
Transparent PNGs drop onto any background in a design tool. White and Black suit a slide or a plain post.
Tips and pitfalls
Long videos. The whole soundtrack is decoded into memory, about 23 MB per stereo minute at 48 kHz. A two-hour film may be too much for a phone; trim it first.
Unsupported audio. Browsers decode AAC, MP3, Opus and Vorbis inside MP4, MOV and WebM files. Some camera formats use PCM or AC-3 audio that only certain browsers handle. If decoding fails, try another browser or extract the audio first.
Loudness is not perceived volume. The waveform shows sample peaks. A heavily compressed song looks like a solid block even though it may not sound louder than a dynamic recording.
How to read the result
The stats give the audio length, channel count, sample rate and the loudest peak in dBFS. A peak at 0 dBFS means the sound reaches full scale and may be clipped.
FAQ
Can I make a waveform image from an MP4?
Yes. Drop the MP4 here and the soundtrack is decoded and drawn at once. Any video your browser can play works, including MOV and WebM, as long as its audio is in a common codec like AAC or Opus.
Why does the tool say no soundtrack could be decoded?
Either the video has no audio track, as with many screen recordings and GIF conversions, or the audio uses a codec this browser cannot decode. Try Chrome or extract the audio with another tool first, then draw it.
Is the waveform scaled to fit?
Yes. The loudest peak in the clip is drawn at 95% of the image height and every other bar is scaled by the same amount. That keeps quiet recordings visible while preserving the relative loudness of each part.
Is my video uploaded to draw the waveform?
No. The file is decoded and drawn by your browser on your own device. Neither the video nor its audio is sent anywhere, so the tool is safe to use with unreleased or confidential recordings.
See also: all Video & Screen tools, Images, Audio, PDF, SVG, Simulations & Screensavers, Generative Art, Chart Makers, 3D Model Viewers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science, Tracker Music.
Related tools
Waveform Viewer
Zoom into any audio file and save its waveform as a PNG image.
Video Info Inspector
Read the resolution, frame rate, bitrate and length of any video file.
Contact Sheet Generator
Turn a video into one image of evenly spaced thumbnails.
Video Color Analyzer
See a video's colour barcode, palette and average brightness.
Extract Audio From Video
Rip the audio track from a video to MP3 or WAV.