How to compare two audio files online
Comparing two versions of a track sounds simple: play one, then the other. In practice that is the least reliable way to hear a difference. By the time the second file starts, your ear has reset, the music is in a different place, and one version is probably louder. A proper A/B comparison fixes all three.
Play both at once, switch instantly
Auditory memory for fine detail lasts a few seconds. If switching means stopping one player and starting another, you compare a memory with a new sound, and the gap is longer than the detail you are listening for.
The reliable way is to run both files in sync from the same moment and switch which one you hear without stopping playback. The switch lands on the same beat in the other version, so the only thing that changes is the version itself.
Match the loudness first
A version that is even 1 dB louder tends to sound fuller, brighter and better. Before judging anything else, bring both to the same perceived loudness: by ear with a gain trim, or automatically by integrated loudness (LUFS).
Keep the files lossless
Many players and messaging apps re-encode audio. If the tool compresses your files, you end up comparing two copies of a codec, not your two versions. Use a tool that plays WAV, FLAC or AIFF bit for bit.
Doing it in audiotoggle
The compare tool needs no account and plays the files from your device; nothing is uploaded.
- Open the compare tool and pick file A and file B (or drop them in).
- Press Play & Compare: both start together.
- Hold the big button, or the space bar, to hear B; release for A. On a phone, tip it toward you.
- Open Adjust levels and switch on auto-match to level both by LUFS.
- Use the arrow keys to jump back two seconds and listen to a passage again.