Free Online Audio Quality Checker
Is that file really lossless? A spectral detective.
Drag & drop your audio file here
or
Max file size: 100 MB · MP3, WAV, FLAC, OGG
Original
beats per minute
musical key
No settings needed — the quality report appears automatically once your file is decoded.
Processing…
Result
How it works
The Audio Quality Checker is a spectral detective for your music library. Upload a file and it reports clipping percentage, true peak (inter-sample peak estimate), integrated LUFS loudness, dynamic range, and the spectral rolloff point — the frequency where the highs give up.
The headline is the verdict: "likely-lossy" when the spectrum shows the brick-wall cutoff of a lossy encoder (abrupt end below 16 kHz, steep shelf, near-silence above it), "clean" otherwise. Treat it as a strong hint, not a certificate — it cannot prove provenance, and dull-but-lossless sources can look band-limited.
Analysis is 100% client-side: your audio is decoded and measured inside your own browser tab, so files never leave your device and nothing is ever uploaded to a server.
Frequently asked questions
Can this prove a file is lossless?
No — and be skeptical of any tool that claims it can. This checker is a heuristic: it looks for the spectral fingerprints lossy encoders typically leave (an abrupt high-frequency cutoff, a steep shelf, very little energy above it). A "likely-lossy" verdict means the file looks like it went through a lossy encoder; a "clean" verdict means no such fingerprint was found. Neither is proof of the file's history — a WAV transcoded from a 128 kbps MP3 will still look lossy, and a genuinely lossless recording of a dull source can look band-limited.
What does "likely-lossy" actually mean?
It means the spectrum ends abruptly below 16 kHz with a steep drop-off and almost no energy above the cutoff — the brick-wall signature of MP3/AAC-style encoders, which throw away high frequencies to save bits. Natural recordings roll off gradually instead.
Why does clipping matter for quality?
Clipped samples (hitting 0 dBFS) are permanently distorted — the waveform tops are chopped flat, which sounds harsh, and the damage cannot be undone. Heavy clipping can also mask the spectral clues the lossy check relies on, so the report flags it prominently.
Is there a file size limit? Is it private?
Files up to 100MB are supported. All analysis — spectrum, loudness, peaks — runs entirely in your browser. Your audio never leaves your device.