Audio quality analysis that runs entirely in your browser.
Privacy first. Your file never leaves this page. Decoding,
analysis, and rendering all happen locally in your browser — nothing is
uploaded or stored. The server only delivers the page itself.
Spectrogram
The main view — frequency (vertical) over time (horizontal),
brightness showing energy. Lossy encoding leaves a sharp horizontal edge where
high frequencies were discarded; true lossless fills the spectrum to the top.
Quality cutoff
Spectre runs an FFT across 20 segments of the track and finds
where the spectrum consistently drops off. A ceiling well below 20 kHz means
the audio was encoded at a lower bitrate than its container claims — shown in
File Info as an approximate kHz value.
Peak envelope
The dashed line traces the highest frequency carrying real
energy at each moment. A flat horizontal ceiling is the signature of lossy
encoding. Toggle it from the sidebar.
Quality cutoffs
Overlays reference lines for the 128 / 192 / 256 / 320 kbps
frequency ceilings, so you can eyeball where your file lands.
Analysis badge
The verdict. For lossless containers (FLAC, WAV, ALAC) it
confirms genuine full-spectrum audio or flags a fake lossless transcode.
For MP3 it estimates the true bitrate tier. Opus and Ogg are judged by bitrate,
since they preserve high frequencies even when compressed.
File info
Duration, sample rate, channel count, and size — read straight
from the decoded audio. Playback sample rate is shown when it differs from the
file's.