Free tool
Drop a finished chapter and instantly see whether your peak, loudness and noise floor meet Audible's specs — with a plain-English fix for anything that's off. Runs entirely in your browser; your audio stays on your device.
Try it
The fastest way to catch a rejection before you submit — no plugins, no signup.
MP3, WAV, M4A or FLAC — up to 25 MB. We'll measure it against the Audible spec.
How it works
The checker decodes your file and measures peak, RMS loudness and the quietest half-second of room tone — all on your machine, no server round trip.
Step 1
MP3, WAV, M4A or FLAC — up to 25 MB.
Step 2
Peak, RMS loudness and noise floor are computed in your browser.
Step 3
Each spec shows pass or fail with the number and a fix tip.
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