Maztr's free online Audio Frequency Viewer is a quick and easy tool you can use right in your browser, without downloading any software, to view the spectrum of sound frequencies in your audio files. No account or login is required to use it.

Our Audio Frequency Viewer can show you a visual illustration of your audio files and help you identify the frequencies they contain - a "visual sound image". This image is also known as a Spectrogram and allows you to "see" your audio files. It's similar to the idea of a music score, except it records sound frequencies instead of musical notes.

Want to see the sound frequency spectrum from your audio files in real time? Click here to use our free Audio Spectrum Analyzer. If you want a detailed analysis of your audio files, click here to use our free Audio File Analyzer. We have many more free tools for your audio files. Click here to check them out.

How do I use the Audio Frequency Viewer?

1. In the "Upload Audio File" section above, drag and drop or click to select the file from your local device.
2. If you want to change your selected audio file, hover or click the file then click "Remove".
3. Choose your Spectrogram Image settings. You can select the size of the image output in pixels and the sound frequencies in kHz that you want displayed. There are also options to remove lines, headings and text from the image output, or display a printer-friendly version.
4. Click the "Upload" button to display the Spectrogram Image of your audio file.
5. The image will be displayed in a size to fit the margins of this page. If you want to see the full sized image, click on it to open it in a new window.

What information is shown on the Spectrogram Image?

• The horizontal axis shows time.
• The vertical axis shows frequencies in kHz.
• Amplitude (audio signal magnitude) is shown through varying colors on the image.
• If the audio file has more than one channel, these are displayed starting with Channel 1 at the top. For stereo recordings, Channel 1 is the left and Channel 2 the right channel.

What is a Spectrogram?

A Spectrogram is a visual representation or image of the spectrum of sound frequencies in a sound file. Maztr's Audio Frequency Viewer can produce a Spectrogram — a visual sound image — of your audio files.

What is the difference between a Waveform and a Spectrogram?

A Waveform only shows changes in a sound's amplitude over time — the classic up and down wavy sound line. In contrast, a Spectrogram shows changes in sound frequencies over time, with amplitude overlaid through varying colors on an image. As a result, a Spectrogram provides much more information and allows you to see details that can't be seen in a Waveform. Problems in a sound mix can be identified and fixed more easily.

What is a Spectrograph?

A Spectrograph is a device or software that creates a Spectrogram. Maztr's Audio Frequency Viewer is therefore a Spectrograph.