Audio Analyser
Inspect an audio file or your live microphone: duration, sample rate, peak and average level, clipping, waveform, frequency spectrum and spectrogram. Everything stays on your device.
What this analyser shows
Drop in an audio file and it reports the duration, sample rate and channel count, how loud the file is, and whether it clips. It draws the waveform, the average frequency spectrum and a spectrogram so you can see what is in the sound and when. The microphone mode does the same live, which is handy for checking a room, a speaker or a tuning note.
Reading the numbers
| Measure | What it means |
|---|---|
| Peak level | The loudest single sample, in dBFS. 0 dBFS is the digital maximum. Peaks at or near 0 mean there is no headroom. |
| Average level (RMS) | The average energy of the file, which tracks perceived loudness better than the peak. It is not a LUFS loudness measurement. |
| Crest factor | Peak minus RMS. Heavily compressed music is often under 10 dB. Speech and acoustic recordings are higher. |
| Clipped samples | Samples at full scale. A few can be harmless, but many in a row means audible distortion. |
| DC offset | A constant shift of the waveform from zero. Small values are normal, large ones can cause clicks. |
| Strongest frequency | The loudest frequency averaged over the whole file, with its nearest musical note. For a single tone it is the pitch. For music it is usually a bass note or a dominant instrument. |
Spectrum and spectrogram
The spectrum shows how much energy sits at each frequency, from deep bass on the left to treble on the right, on a logarithmic scale like human hearing. The spectrogram adds time: brighter colors mean more energy at that frequency at that moment. A sharp cutoff near 16 kHz often reveals a low-bitrate MP3, and horizontal lines show steady tones such as hum.
Private and device-based
Files are decoded and analysed by your browser and are never uploaded. The microphone is only opened when you press start, nothing is recorded, and it is released when you press stop or leave the page. Supported formats depend on your browser, and files over 150 MB are refused to avoid running out of memory. To work with the results, the Epoch Time Converter and Data Storage Converter help with timestamps and file sizes.
Frequently asked
Is my audio uploaded anywhere?
No. Files are decoded and analysed by your browser on your device, and the microphone feed is only analysed live. Nothing is recorded, stored or sent to Curious Assistant or anyone else.
Which audio formats can it open?
Whatever your browser can decode. MP3, WAV, AAC/M4A and OGG work in all modern browsers, and FLAC and Opus work in most. If a file fails, convert it to WAV or MP3 and try again.
What does dBFS mean?
Decibels relative to full scale, the digital maximum. 0 dBFS is the loudest a digital file can be, and everything else is negative. A peak of −1 dBFS has a little headroom, while exactly 0 suggests clipping.
Is the RMS value the same as LUFS loudness?
No. RMS is a simple average of the signal energy. LUFS applies frequency weighting and gating to estimate perceived loudness for streaming standards. RMS is a useful comparison, but not a substitute.
How accurate is the frequency and note reading?
For a clear single tone it is accurate to a few cents or better. For music with many instruments or noise, the strongest frequency is just the loudest component, so the note shown may not match the melody.
Why does the microphone mode not work?
Browsers only allow microphone access on secure (https) pages and after you grant permission. Check the permission for this site in your browser settings and that no other app has locked the microphone.