See exactly what's
in your master.
Upload a mix or master and get real loudness metering, frequency and phase analysis, a live parametric EQ, and specific, actionable fixes — all computed from your actual file, not generic advice.
Click any card above to load a synthesized demo track and jump straight to that panel — no upload needed.
Click to upload or drag an audio file here
WAV, MP3, FLAC, AIFF — analyzed entirely in your browser, nothing is uploaded anywhere
File Info
Loudness & Dynamics
Integrated loudness is measured per ITU-R BS.1770-4: K-weighting filters, 400ms gated blocks with 75% overlap, absolute gate at −70 LUFS and relative gate at −10 LU below the absolute-gated mean. Commercial masters typically target around −14 to −9 integrated LUFS with true peak below −1 dBTP. True peak here uses 4x linear-interpolation oversampling as an approximation of the standard's polyphase filter — close, but a dedicated meter may read slightly differently on inter-sample peaks.
Mix Diagnosis — What To Fix
Computed directly from this file's frequency balance, phase correlation, peak headroom and loudness — not generic advice. Green checks are healthy, amber/red flag things worth addressing before your next master pass.
Transient Analysis — Kick/Drum Detail
Detects percussive hits (kick/snare-type transients) and measures how hot they sit above the mix, how long they ring out, and whether lingering low end afterward is the transient itself or the bass note underneath it merging in.
Version History & Compare
Every file you analyze is automatically logged here (metrics only, stored locally in your browser — no audio is saved). Select two versions to see exactly what changed between them, the same way we've been comparing versions manually.
Loudness History Timeline
Shows how loudness moves across the track. A momentary line that swings wildly against a flat short-term line usually means transient-heavy material; a short-term line that drifts far from the integrated average across sections can flag inconsistent balance between verses/choruses or intro/outro.
Parametric EQ
Drag any node to change its frequency and gain live during playback. Scroll on a node to adjust its Q (bandwidth). This EQ sits permanently in the playback chain — it's separate from the A/B modes below, so you can shape the sound directly and hear the analyzer and A/B modes respond to it.
A/B Compare — Reveal the Gap
Play the same file three ways: as-is, gain-matched to Spotify's −14 LUFS target, and an "Enhanced" pass that trims 250–500 Hz mud, lifts 2–5 kHz presence, and adds gentle glue compression — all landed at the same −14 LUFS. If Enhanced sounds noticeably punchier than Normalized at equal loudness, that gap is exactly what's separating you from a commercial-feeling master. Switch modes below, then hit Play in the panel underneath.
Frequency Spectrum (live playback analysis)
Spectrogram — Frequency Over Time
The whole track's frequency content plotted over time — brighter/hotter colors mean more energy at that frequency at that moment. Great for spotting resonant buildups, where mud or harshness actually lives in the arrangement, and how long low-end content rings out.
Vectorscope & Phase Correlation
The scope shows L/R as a Lissajous pattern: a vertical line means perfectly mono/correlated, a wide circle means very wide or phase-incoherent stereo. Correlation near −1 is a real problem, it means content will cancel out in mono playback (phones, clubs, some Bluetooth speakers).
Stereo Field Map — Width by Frequency
The same idea as the spectrogram, but for stereo width instead of time: every frequency in the track summed up and plotted by how centered (mono) or spread (wide) it is. Bass generally belongs low on this chart — wide bass is a common mono-compatibility problem.
Reference Track Compare
Load a commercial reference (or an earlier version of your own track) to compare against. Playback is automatically level-matched to −14 LUFS on both, so you're judging tone and balance, not just "louder sounds better."
Streaming Platform Loudness Preview
Most streaming platforms normalize playback loudness to their own target. If your integrated loudness is louder than the platform's target, they'll turn your master down to match — so mastering hotter than a platform's target buys you nothing there, it just eats into your peak headroom for no benefit. If you're quieter than the target, most platforms turn you up, which can also raise your true peak above 0 dBTP if you had little headroom to begin with.
Waveform — full track
Click the waveform to jump playback there, or drag to select a region to zoom into below.
Sample-level Zoom
Gain Automation Preview
Drag a selection on the Waveform panel above, then apply a gain boost to just that region — the way you'd automate a quiet section up in your DAW. This shows you the before/after LUFS and crest factor without touching your DAW project, so you can see if it's worth doing before you commit.