Legal

Terms

What this tool promises

It provides local planning and measurement tools: manuscript word-count estimates, five published ACX audio checks, podcast loudness normalization and chapter-to-chapter consistency flags. The tools are free to use and need no account.

A manuscript length or PFH budget is an estimate based on the pace, rate and production ratio you choose, not a quote or guarantee. A batch consistency flag is an editorial prompt, not an ACX rule. The LUFS true-peak value is a four-times estimate, not certified broadcast measurement.

What it does not promise

It cannot promise your audiobook will be accepted. ACX rejects files automatically against the five measurements described here, and separately a person reviews submissions for pronunciation, extraneous sounds, consistency across the book, credits and section headers. This tool measures none of those and makes no claim about them.

It is not affiliated with, endorsed by or connected to ACX, Audible or Amazon. Those names appear here to describe whose published requirements are being measured, which is the only way to describe them.

The developer API

The optional developer API has terms of its own, in addition to the rest of this page.

  • Accounts. A developer account is for one person or one organisation. Keep your API keys secret; what is done with a key is done by its holder. Revoke a key you think has leaked.
  • Your rights to what you send. Send only audio and text you own or have permission to process. You keep every right you had in it; we take none, and we use it for nothing but the job you asked for.
  • No voice cloning. The API does not clone, imitate or train on any voice, and you may not use it to try. Its text-to-speech reads with built-in synthetic voices only.
  • Synthetic speech is for listening, not for sale as narration. Text-to-speech output is labelled synthetic in its tags. ACX does not accept it, and you may not remove the label or present it as a human performance.
  • Retention. Your upload is deleted when the job finishes, and results expire within 48 hours. Download what you want to keep.
  • Plans and limits. The free plan and its quotas are stated on the developers page. Pro is free during the beta; the price shown beside it is what we intend to charge afterwards, and nothing is ever charged without asking you first. We may change quotas, suspend a key that is abused, or withdraw the API, with notice on that page.
  • As is. The API carries no availability commitment and the same warranty as everything else here, which is none: a verdict from the API is a measurement, not a promise that ACX will accept a file.

Keep your original

The corrected file is a new encode, and MP3 encoding is lossy. Always keep your master recording. Do not use the output of this tool as the source for further editing.

No warranty

The tools and the developer API are provided as is, without warranty of any kind. The tools run on your device, on your file, and we never see either.