Two versions of the same mix. You keep picking the second one — because it's 0.8 dB louder, not because it's better.
Five seconds · no audio required
Below are two renders of the same song. One of them is louder. Decide which one you'd keep — then open the answer.
Neither. They are the same render. B was played back 0.8 dB louder — the only difference between those two panels is a gain change, and you can see it in the bar heights once you know to look.
That much level never registers as volume. It registers as better — more open, more present, more finished. It is the single most reliable way to pick the wrong mix, and it is the first thing Blind A/B measures out.
One file · macOS, Windows, Linux · runs offline
What it takes away
Blind A/B removes all three, then gets out of the way. What's left is the sound.
Filenames are hidden and the A/B sides are shuffled on every load. You can't know which one is "v7" until you've already decided.
Real BS.1770 K-weighted, gated LUFS measurement, matched attenuate-only — the quieter file is never pushed up to fake a win.
Two-stage cross-correlation finds any start offset between the renders and locks them to the sample, so you always hear the same moment.
How a pass goes
WAV, AIFF or MP3. They're measured, matched and aligned before anything plays.
Switch freely, or let it flip for you. No labels, no numbers, no hints.
Press SPACE to catch whatever is playing as a glowing orb, then drop it on a section to lock that section's pick. Verse, chorus, bridge — decided one at a time.
See which mix won each section, audition the comp you just built out of your blind picks, and render it out.
Where the audio goes
Every decode, measurement and render happens on your machine. There is not one network request at runtime — not analytics, not a licence check, not a font.
Which means you can load a record that isn't out yet. And you don't have to take that on faith: pull your Wi-Fi and the tool behaves exactly the same.
The details
| Format | One self-contained HTML file — double-click it |
|---|---|
| Platforms | macOS, Windows, Linux |
| Requires | Any modern browser with Web Audio — Chrome, Safari, Edge, Firefox |
| Input | WAV, AIFF, MP3 |
| Export | WAV — 32-bit float, 24-bit or 16-bit, at the source's native sample rate |
| Safety | True-peak warnings for inter-sample clipping |
| Also included | Native macOS app — universal, macOS 11.3+ |
| Install | None. No account, no sign-in, no dependencies |
| Sales | Final — an instant download, so no refunds. Broken download or won't run? Email me. |
Built by a working producer who got tired of picking the louder file.
All sales final · if it won't run, email me and I'll sort it out