Free Online Spectrogram Generator
See any audio as a spectrogram, or hide an image inside sound - free, in your browser, nothing uploaded.
Everything runs right in your browser. Your files never leave your device - nothing is uploaded.
Spectrogram Generator - See Audio, Hear Images
Turn any sound into a spectrogram online, right in your browser. Drop an audio file and this free spectrogram generator runs a Short-Time Fourier Transform and paints time on the x-axis, frequency on the y-axis and loudness as color, with log or linear scales and several color maps. Then flip it around: drop an image and the tool resynthesises audio whose own spectrogram looks like your picture. Nothing is uploaded, no plugin, no sign-up, and your files never leave your device.
- Audio to spectrogram.
- Drop a track and watch its frequencies over time appear as a sharp, colorful spectrogram you can download as a PNG.
- Image to sound.
- Upload a picture and the tool hides it inside audio, so the sound's own spectrogram reveals your image.
- Log, linear and color maps.
- Switch between log and linear frequency scales and Magma, Aurora or grayscale palettes to read the detail you need.
How to make a spectrogram online
From an audio file to a downloadable spectrogram in three steps, free and instant in your browser.
Drop your audio
Drop an audio file (MP3, WAV, M4A, FLAC, OGG) onto the tool or pick a song from your library. It is decoded locally, so nothing leaves your device.
Read the spectrogram
An STFT paints frequency over time with loudness as color. Pick a log or linear scale, an FFT size and a color map to bring out exactly the detail you want.
Download or go reverse
Save the spectrogram as a PNG, or switch to image-to-sound mode and turn a picture into a WAV whose spectrogram shows the image.
Spectrogram tool at a glance
- Short-Time Fourier Transform engine
- STFT
- Switchable frequency scales
- Log / linear
- Download the spectrogram image
- PNG
- Hide a picture inside audio
- Image to sound
- In your browser, nothing uploaded
- Free
- Export the resynthesised audio
- WAV
Everything you need to read sound
A real time-frequency view, not just a waveform, plus the reverse trick that hides images in audio.
- Sharp time-frequency view
A Hann-windowed STFT turns your audio into a clean spectrogram so you can see harmonics, noise, sibilance and silence that a waveform simply cannot show.
- Log and linear scales
Read bass detail on a log frequency scale or inspect the full spectrum on a linear one, and choose Magma, Aurora or grayscale color maps to suit the material.
- Image to sound
Drop any picture and the tool resynthesises audio with an inverse STFT, so the sound's own spectrogram draws your image. Share a track with a secret picture inside.
- Download and keep
Save the spectrogram as a PNG for notes, artwork or analysis, and export the image-to-sound result as a WAV you can play anywhere.
Who uses a spectrogram?
Anyone who needs to see what a sound is really made of, or to play with sound as a visual.
- Producers
Spot harsh resonances and muddy buildup in a mix.
- Mixing engineers
Find sibilance, rumble and masking before they bite.
- Sound designers
Inspect textures, transients and noise floors closely.
- Musicians
See pitch, harmonics and vibrato of a performance.
- Field recordists
Identify birdsong, hum and unwanted background noise.
- Podcasters
Catch clicks, plosives and hiss in spoken audio.
- Students
Learn acoustics and how the Fourier transform looks.
- Artists
Hide pictures and text inside sound for fun or art.
- Restoration
Locate noise and artifacts before cleaning a recording.
Why use this spectrogram generator
See what your ears miss, and turn images into sound, without installing a thing.
- See problems you cannot hear yet
Resonances, sibilance, low rumble and digital noise jump out on a spectrogram long before you can name them by ear, so you fix the real issue instead of guessing.
- Make spectrogram art
Image-to-sound mode hides any picture or text inside an audio file, the way artists have tucked images into their tracks for years. Make your own and share it.
- Nothing to install
The whole thing runs in your browser with the Web Audio API. No plugin, no app, no account, and your audio and images never leave your device.
Spectrograms and the Fourier transform, explained
Loved by people who look at sound
“Being able to drop a file and instantly see the spectrogram in the browser is a lifesaver. I catch resonances and noise floors in seconds without loading a single plugin.”
Elena Fischer
Sound designer
“The log scale makes low-end problems obvious. I clean up mud and harsh resonances way faster now, and the PNG export goes straight into my mix notes.”
Tom Bradley
Music producer
“Image-to-sound is pure magic. I hid my logo inside a track and people freaked out when they opened the spectrogram. So fun, and it runs right in the browser.”
Aiko Tanaka
Digital artist
Spectrogram FAQ
- What is a spectrogram generator?
- It is a tool that turns audio into a spectrogram, a visual plot of frequency over time with loudness shown as color. This one also works in reverse, turning an image into sound whose spectrogram shows the picture, all in your browser.
- Is it free?
- Yes. The spectrogram generator is completely free, needs no sign-up, and runs entirely in your browser. Your audio and images are processed locally and never uploaded to a server.
- How does image to sound work?
- Your image is read as a spectrogram: columns are time, rows are frequency, brightness is loudness. An inverse Short-Time Fourier Transform resynthesises audio so that the sound's own spectrogram looks like your image when you view it.
- What audio files can I use?
- Common formats including MP3, WAV, M4A, FLAC and OGG. The file is decoded with the Web Audio API right in your browser, so it is analyzed locally and nothing is uploaded.
- What is FFT size?
- FFT size sets how each slice of audio is analyzed. A larger size (like 4096 or 8192) gives finer frequency detail but blurs timing, while a smaller size (like 1024) gives sharper timing but coarser frequency. Try a few to suit your material.
- Should I use a log or linear scale?
- Use a log scale to read pitch and low-end detail the way you hear it, with each octave given equal space. Use a linear scale when you care about evenly spaced high frequencies. You can switch between them at any time.
- Can I download the spectrogram?
- Yes. You can save the spectrogram as a PNG image, and in image-to-sound mode you can export the generated audio as a WAV file to play or share anywhere.
Saw the sound - now shape it
You can read any track as a spectrogram. Take the next step and split it into stems or polish it to a release-ready master with our AI tools.